RU2700560C1 - Gigaspacewire communication interface device - Google Patents

Abstract

FIELD: computer equipment.

SUBSTANCE: invention relates to GigaSpaceWire communication interface device. Device comprises a data output unit, a data reception unit, a data flow control unit, a control unit, a transducer of transmitted symbols, a symbol transceiver, a received symbol converter, a connection check unit, a decoder, a parameter register and a decoder.

EFFECT: elimination of loss of throughput capacity at increase of device operating frequency and transfer speed in interface.

3 cl, 16 dwg, 4 tbl

Description

Description of the invention

The present invention is a communication interface device (system) and relates to digital computing, namely, high-speed communication systems for high-performance multiprocessor computing systems with distributed information processing and local area networks based on SpaceWire technology [ECSS Standard ECSS-E- 50-12A, "SpaceWire, Links, Nodes, Routers and Networks", Issue 1, European Cooperation for Space Data Standardization, February 2003.]. This device is intended, in particular, for use in the construction of multiprocessor computing systems with a distributed architecture, used in embedded applications, including on-board computer systems, as well as on-board local area networks.

As an analogue from the prior art, the communication interface described in the patent is known in which, when transmitting data on a serial communication channel, the 8b / 10b transform is used to represent eight-bit characters as 10-bit codes. In devices that communicate through this communication interface, every eight bits of the original sequence are replaced with 10 bits in accordance with certain rules. As a result, for 256 possible combinations of eight input bits, 1024 possible combinations for 10 output bits are obtained. But of these 1024 combinations, only 256 are allowed, and the rest are forbidden. As a rule, such redundancy is used in order to increase the coding noise immunity (if a forbidden sequence is detected during reception, a transmission error is recognized). In addition, such redundancy improves the self-synchronizing properties of the code, since it eliminates the possibility of long sequences of zeros and ones appearing in the transmitted bit chain, which ultimately helps to increase the reliability of the device. When data is received, 8b / 10b decoding is performed, that is, eight bits are mapped to each group of 10 bits.

The disadvantage of this approach is the inability to transmit special control codes along with data symbols. Special control codes are needed to support system functions and real-time control, which significantly limits the scope.

A known conversion device 8b / 10b, [US Patent 06977599 B2. 8B / 10B encoding and decoding for high speed applications, Apr 30, 2002]. used in the FibreChannel standard. The device contains an 8b / 10b encoding unit, an output 10-bit shift register that provides conversion of parallel 10-bit codes to a serial bit stream output to the communication interface, an input 10-bit shift register that provides reverse conversion of a serial bit stream to parallel 10-bit codes and decoding unit 8b / 10b. The device operates at a local frequency 10 times lower than the bit rate in the communication interface. The use of the code 8b / 10b allows the use of a single data transmission line in the communication channel, since when encoding 8b / 10b it is possible to transmit, along with data symbols, a special built-in clock symbol for synchronizing interacting devices.

As a drawback, it should be noted that the device does not provide real-time transmission of various special control codes (system interrupts, system time markers and other control signals necessary for control at the system level), since it is not possible to insert a control code into the sequence of transmitted eight-bit characters data of one frame. The need to wait for the end of the transmission of the next data frame leads to significant time delays in performing system functions. In addition, the inability to implement system mechanisms in real time significantly reduces the scope.

A serial communication interface is known that implements a DS-coding method in accordance with the SpaceWire standard [ECSS Standard ECSS-E-50-12A, "SpaceWire, Links, Nodes, Routers and Networks", Issue 1, European Cooperation for Space Data Standardization, February 2003.] and widely used for transmitting bit streams between processing nodes in airborne distributed computing complexes. The use of data lines and strobe (D- and S-signals) in each direction in the communication interface allows for high-speed transmission of data bits in a wide speed range from 2 Mbit / s to 400 Mbit / s. A simple implementation of the procedure for generating data packets based on the use of service (control) characters of the end of the EOP packet (End Of Packet) allows transmitting information symbols in the form of packets of arbitrary length. This feature simplifies the structure of switching nodes (switches and hubs) used to transmit and switch bit streams from airborne sensors to processing nodes in distributed computing complexes.

The disadvantage of the SpaceWire interface is the presence of jitter (variation of the delay time) between the parallel transmitted D- and S-signals in the physical channel. Due to the need to use two lines for transmitting data bits and gating signals, DS coding places rather stringent requirements on the bevel (phase shift) and jitter of D and S signals, which makes it difficult to use at distances of more than 10 meters. Also, the presence of two lines for each direction of transmission makes it difficult to use galvanic isolation due to various delays at the isolation itself, which significantly limits the scope of SpaceWire devices in on-board distributed computing complexes.

A device for a communication interface [Patent GB No. 91304711.4. Communication interface for serial transmission of variable length data tokens / Priority 05/25/90, No. 9011700. Data of filing 05/24/91. Data of publication 11/27/91. Bulletin 91/48 of European Patent Office. Publication number 0458648 A2] for use in a communication system connecting at least two computers, the communication interface device comprising a control unit, a data flow control unit, a data output unit and a data receiving unit, the data and gating inputs of which are respectively data and gating inputs device interface with a channel for receiving information, data outputs and gating device interface with a channel for issuing information are respectively data outputs and gating blocks and data output. The device’s flow control unit, using special FCT (Flow Control Token) flow control characters, implements a lending mechanism that allows the use of buffers of a limited size for receiving and transmitting packets of unlimited length.

The disadvantage of this device communication interface is the limitation of the distance between the interacting parties and the absence of galvanic isolation, which can cause failures and malfunctions due to short circuits.

The closest analogue to the claimed is a communication interface device for the SpaceWire network [RF Patent No. 2483351 C1 for invention, application No. 2012115639/08, declared. 04/19/2012, publ. 05/27/2013 Bull. No. 15]. A known device that implements the GigaSpaceWire communication interface comprises a data output unit, a transmit symbol converter, a symbol transceiver, a received symbol converter, a data receive unit, a connection test unit, a control unit and a data flow control unit, the output of the request for issuing a flow control symbol of which is connected to the input of the data output unit of the same name, the output of the readiness of the flow control symbol being connected to the input of the data flow control unit of the same name, You confirm the receipt of the flow control symbol and confirm the reception of the information symbol of which is connected respectively to the outputs of the data receiving unit and the inputs of the control unit of the same name, the output of the character encoding error of which is the output of the character encoding error of the device system interface, the synchronization input of which is connected to the inputs of the data output unit of the same name , data receiving unit, data flow control unit and control unit, reset input of the system interface of the jav device is the reset input of the control unit, the first reset output of which is connected to the reset inputs of the data output unit, the transmitter of transmitted characters and the symbol transceiver, the second reset output of the control unit is connected to the reset input of the data receive unit, the output “received NULL” of which is connected to the same input of the control unit, The input for reading data from the system interface of the device is the input of the data receiving unit of the same name, the data outputs for receiving and the readiness of the data for receiving are the corresponding output In the system interface of the device, the credit error output of the system interface of the device is the output of the data flow control unit of the same name and is connected to the input of the control unit of the same name, the third reset output of which is connected to the reset input of the data flow control unit, whose acknowledgment inputs and data reception permissions are connected with the outputs of the same name, respectively, of the data output unit and the data reception unit, the output readiness output of the data of the system interface of the device the two is the output of the data output unit of the same name, the recording and data inputs for issuing the system interface of the device are the corresponding inputs of the data output unit, the connection error of the connection verification unit is connected to the input of the control unit of the same name, the information input of the symbol transceiver is connected to the output of the transmitted symbol symbol 8b, the readiness output of the character issuance of which is connected to the readiness input of the data output unit, the information output and the character type output of which are respectively connected with the data inputs and the symbol type of the transmitter of the transmitted symbols, the output of the special symbol attribute of which is connected to the input of the symbol type of the symbol transceiver, the output of the bit signals of which is the same output of the device communication interface, the local synchronization output of the symbol transceiver is connected to the inputs of the transmitter of the transmitted symbols, converter received characters, control unit, data receiving unit and data output unit, input recording the control code of which is the input of the system interface of the device of the same name, the output of the readiness for issuing the control code of which is the output of the data output unit of the same name, the input of the control code for the output of which is the input of the system interface of the same name, the output of the received control code of which is the output of the data reception unit of the same name, output the readiness of the accepted control code of which is the output of the device system interface of the same name, the read input is controlled its code of which is the input of the data reception unit of the same name, the information input and the input of the symbol type of which are connected respectively to the outputs of the converter of the received symbols, the information input of which is connected to the same output of the symbol transceiver, the output of the symbol 8b of which is connected to the information input of the connection check unit, sign input the special character of which is connected to the input of the converter of the received symbols and the output of the transceiver of the symbols of the same name, the error output is which is connected to the input of the control unit of the same name, the connection establishment input of which is connected to the output of the connection check unit of the same name, the connection attribute input of which is connected to the input of the received symbol transformer of the same name and the symbol transceiver output of the same name, the reception synchronization output of which is connected to the input of the connection check unit of the same name , the input of the bit signals of the symbol transceiver is the input of the same device communication interface, m, the data flow control unit contains a credit request generator, a received symbol counter, a transmitted symbol counter and a credit error detector, the first output of which is a credit error output of the data flow control unit, the data reception permission input and the ready control output symbol input are respectively the first and second the inputs of the credit request generator, the third input of which is connected to the status output of the counter of received symbols, the synchronization input of which is is the synchronization input of the data flow control unit and connected to the synchronization inputs of the credit request generator, the counter of transmitted symbols and the credit error detector, the reset input of the data flow control unit is connected to the reset inputs of the credit request generator, the counter of the received symbols, the transmitted symbol counter and the credit error detector, the first information input of which is connected to the output of a credit error of receiving a counter of received symbols, the first control input of which is connected is connected with the output of the credit request generator and is the output of the request for issuing the flow control symbol of the data flow control unit, the second control input of the counter of received symbols is the input of the acknowledgment of the information symbol of the data flow control unit, the input of the acknowledgment of receipt of the flow control symbol of which is the first control input of the transmitted counter characters, the second control input of which is the confirmation input of the information symbol of the control unit by eye data, second information input credit error detector connected to the output state of the counter of transmitted symbols; the control unit contains a status register, a new state generation unit and a control signal generator, the reset input of which is a reset input of the control unit and connected to the reset inputs of the status register, the status output of which is connected to the first control input of the new state generation unit and to the control input of the control signal generator , the connection establishment output, the disconnect error output and the status register symbol encoding error output are the outputs of the control unit of the same name the synchronization input of which is the synchronization input of the status register, the status control input of which is connected to the state control output of the new state generation unit, connection establishment inputs, credit errors, disconnection errors, symbol encoding errors, acknowledgment of receipt of the flow control symbol, and acknowledgment of receipt of the information symbol which are the inputs of the same name of the control unit, the local synchronization input of which is connected to the inputs of the same name For control signals, the first, second, third outputs of the reset and the output enable transmission of the flow control symbol of which are the outputs of the control unit of the same name, the “Received NULL” input of which is the same name of the unit for generating a new state; the connection verification unit contains a communication support symbol decoder, a communication setup trigger, a standby counter, a first OR element, a second OR element, and an AND element, the output of which is the output of the connection error of the connection verification unit, the information input and the input of which special character is the first and second inputs, respectively the decoder of the communication support symbol, the output of the selection of the communication support symbol which is connected to the first input of the first OR element, the output of which is connected to the data input of the trigger communication ki, the connection establishment output of which is connected to the second input of the first OR element, to the first input of the AND element, and is the connection establishment block connection connection output, the input of the connection indicator of which is connected to the enable input of the decoder, with the inverse reset input of the communication setup trigger and with the first inverse the input of the second OR element, the output of the disconnect sign and the second input of which are connected respectively to the second input of the AND element and the transfer output of the standby counter, the decrement input of which connected to the input of the synchronization flip-flop connection setup and reception timing is input to verify the connection block.

This device supports operation at frequencies of 1 GHz, with a local frequency 10 times less than the frequency of transmission and reception of bits. That is, it allows you to transmit a stream of data bits in a communication interface at a frequency ten times the local frequency at which all other blocks of the device work. However, increasing the cable length and increasing the frequency of data transmission leads to problems with achieving maximum throughput while ensuring constant channel load.

The disadvantage of this technical is the reduction in the utilization rate of the channel capacity when transmitting over long distances and / or with speeds exceeding 1 Gbit / s, due to the rather long idle time of the channel when there is no real data transmission. In such situations, it is not possible to increase the useful bandwidth of the channel, since the applied lending mechanism does not allow efficient use of the maximum share of the bandwidth of the device for the actual transmission of user data characters. At distances of more than 10 meters and at a speed of 1 Gbit / s, a limit of 56 channel characters of the loan amount provided in accordance with the SpaceWire standard when transmitting seven characters of FCT loan request in a row in the above solution is not enough to provide an effective mechanism for transferring loans, since service credit symbols simply do not have time to reach the transmitting interface in time due to physical delays in the cable connecting the interacting devices of the communication interface. Thus, in the absence of credits, the interacting parties are not able to effectively support the transfer, and gaps occur in the channel in data symbol transfer transactions, filled with the transmission of NULL service symbols.

The basis of the present invention is the task of increasing the throughput of the communication interface device while providing enhanced functionality by realizing the possibility of transmitting data without spaces in the form of empty characters when transmitting a constant data stream. The technical result of the invention is to expand the scope of the communication interface device by providing a lending mechanism that is adaptable to specific parameters of the communication channel when transmitting data.

The technical result is achieved by the fact that in the proposed device of the communication interface GigaSpaceWire, comprising a data output unit, a transmit symbol converter, a symbol transceiver, a received symbol converter, a data receive unit, a connection test unit, a control unit and a data flow control unit, a request for issuing a symbol the flow control of which is connected to the input of the data output unit of the same name, the readiness output of the output of the flow control symbol of which is connected to the input of the same name ohm of the data flow control unit, inputs of acknowledgment of receipt of the flow control symbol and acknowledgment of the information symbol of which are connected respectively to the outputs of the data reception unit and inputs of the same name of the control unit, the output of the character encoding error of which is the output of the character encoding error of the system interface of the device, the synchronization input of which is connected with the inputs of the same name data output unit, data reception unit, data flow control unit and control unit, input reset The system interface of the device is a reset input of the control unit, the first reset output of which is connected to the reset inputs of the data output unit, the transmitter of transmitted characters and the symbol transceiver, the second reset output of the control unit is connected to the reset input of the data receive unit, the output of which “received NULL” is connected to the input of the control unit of the same name, the data read input of the system interface of the device is the input of the data reception unit of the same name, data outputs for reception and readiness of data for reception are the corresponding outputs of the system interface of the device, the credit error output of the system interface of the device is the output of the data flow control unit of the same name and is connected to the input of the control unit of the same name, the third output of which is connected to the reset input of the data flow control unit, acknowledgment inputs for the information symbol and reception permission the data of which are connected to the outputs of the same name, respectively, of the data issuing unit and the data receiving unit, the readiness output is As the data of the device’s system interface is the output of the data output unit of the same name, the recording and data inputs for issuing the device’s system interface are the corresponding inputs of the data output unit, the connection error of the connection verification unit is connected to the same input of the control unit, the information input of the symbol transceiver is connected to the output of symbol 8b a transmitter of transmitted characters, the output of the readiness for issuing a symbol of which is connected to the readiness input of the data output unit, information the output and the output of the symbol type of which are connected respectively to the data inputs and of the symbol type of the transmitter of transmitted symbols, the output of the special character flag of which is connected to the input of the symbol type of the symbol transceiver, the output of the bit signals of which is the same output of the device communication interface, the output of the local synchronization of the symbol transceiver is connected to inputs of the converter of transmitted symbols with the same name, converter of received symbols, control unit, unit reception of data and a data output unit, the input of the control code recording of which is the input of the device system interface of the same name, the readiness output of the control code output of which is the output of the data output unit of the same name, the input of the control code for the output of which is the input of the device system interface of the same name, the output of which control code is received is the output of the data reception unit of the same name, the readiness output of the received control code of which is the output of the system int The device interface, the control code reading input of which is the input of the data receiving unit of the same name, the information input and the symbol type input of which are connected respectively to the outputs of the received symbol converter of the same name, the information input of which is connected to the same output of the symbol transceiver, the output of symbol 8b of which is connected to the information input of the block checking the connection, the input of the special character attribute of which is connected to the input of the converter of the same name with the same input in and the output of the symbol transceiver, the output of the coding error of which is connected to the input of the control unit of the same name, the connection establishment input of which is connected to the same output of the connection check unit, the connection sign of which is connected to the input of the transmitter of the received symbols of the same name and the output of the symbol transceiver of the same name, reception synchronization output which is connected to the same input of the connection check unit, the input of the bit signals of the symbol transceiver is of the same name m is the input of the communication interface of the device, wherein the data flow control unit comprises a credit request generator, a received symbol counter, a transmitted symbol counter and a credit error detector, the first output of which is a credit error output of the data flow control unit, a data reception permission input and a ready control input which are respectively the first and second inputs of the credit request generator, the third input of which is connected to the account status output the received symbol counter, the synchronization input of which is the synchronization input of the data flow control unit and connected to the synchronization inputs of the credit request generator, the counter of transmitted symbols and the credit error detector, the reset input of the data flow control unit is connected to the reset inputs of the credit request generator, the received symbol counter, counter the transmitted characters and the credit error detector, the first information input of which is connected to the output of the credit error receiving the counter symbols, the first control input of which is connected to the output of the credit request generator and is the output of the request for issuing a flow control symbol of the data flow control unit, the second control input of the received symbol counter is the input of the acknowledgment of the information symbol of the data flow control unit, the input of the acknowledgment of receipt of the flow control symbol which is the first control input of the counter of transmitted characters, the second control input of which is the confirmation input Nia issuing information symbol data flow control unit, second information input credit error detector connected to the output state of the counter of transmitted symbols; the control unit contains a status register, a new state generation unit and a control signal generator, the reset input of which is a reset input of the control unit and connected to the reset inputs of the status register, the status output of which is connected to the first control input of the new state generation unit and to the control input of the control signal generator , the connection establishment output, the disconnect error output and the status register symbol encoding error output are the outputs of the control unit of the same name the synchronization input of which is the synchronization input of the status register, the status control input of which is connected to the state control output of the new state generation unit, connection establishment inputs, credit errors, disconnection errors, symbol encoding errors, acknowledgment of receipt of the flow control symbol, and acknowledgment of receipt of the information symbol which are the inputs of the same name of the control unit, the local synchronization input of which is connected to the inputs of the same name For control signals, the first, second, third outputs of the reset and the output enable transmission of the flow control symbol of which are the outputs of the control unit of the same name, the “Received NULL” input of which is the same name of the unit for generating a new state; the connection verification unit contains a communication support symbol decoder, a communication setup trigger, a standby counter, a first OR element, a second OR element, and an AND element, the output of which is the output of the connection error of the connection verification unit, the information input and the input of which special character is the first and second inputs, respectively the decoder of the communication support symbol, the output of the selection of the communication support symbol which is connected to the first input of the first OR element, the output of which is connected to the data input of the trigger communication ki, the connection establishment output of which is connected to the second input of the first OR element, to the first input of the AND element, and is the connection establishment block connection connection output, the input of the connection indicator of which is connected to the enable input of the decoder, with the inverse reset input of the communication setup trigger and with the first inverse the input of the second OR element, the output of the disconnect sign and the second input of which are connected respectively to the second input of the AND element and the transfer output of the standby counter, the decrement input of which connected to the synchronization input of the trigger of the communication setup and is the synchronization input of the reception of the connection test block, a parameter register and a decoder are introduced, the control input of which is the selection enable input of the device system interface, the information input of which is connected to the address input of the decoder and the information input of the parameter register, which controls the input of which is the write enable parameter of the system interface of the device, the synchronization input of which is connected to the synchronization progress of the parameter register, the output of which is connected to the parameter inputs of the connection check unit, control unit and flow control unit, the recording input of which is connected to the first enable output of the decoder, the second and third enable outputs of which are connected to the recording inputs of the control unit and connection check unit, the reset input of which is connected to the second output of the reset of the control unit, the control unit further comprising a connection counter, a register of delay constants and a circuit of adenia, the first input of which is connected to the output of the delay constant register, the information input of which is the input of the control unit parameter, the recording input of which is the write input of the delay constant register, the synchronization input of which is the synchronization input of the control unit, the reset input of which is connected to the inputs of the constant constant register and a connection counter, the output of which is connected to the second input of the matching circuit, the output of which is connected to the second control input of the new state control output driver control signals connected with the same input connections counter whose count input is an input local synchronization control unit.

Preferably, the data flow control unit further comprises registers of the first and second constants and a comparator, the output of which is connected to the input of the error sign of the credit error detector, the second output of which is the output of the data output control unit of the data flow control unit, the status output of the counter of transmitted symbols is connected to the first input of the comparator the second input of which is connected to the output of the register of the second constant, the information input of which is connected to the information input of the register of the first constant and is a parameter input of the data flow control unit, the recording input of which includes a recording line of the first constant connected to the recording input of the register of the first constant, and a recording line of the second constant connected to the recording input of the register of the second constant, the synchronization input of which is connected to the same input of the register of the first constants and is the synchronization input of the data flow control unit, the reset input of which is connected to the inputs of the same register of the second constant and the register of the first constant, the output of which oh connected to the information input counter of the received characters.

Preferably, the connection verification unit further comprises a disconnect parameter register and a third OR element, the output of which is connected to a load input of the standby counter, the information input of which is connected to the output of the disconnection parameter register, the information input and recording input of which are respectively the parameter input and recording input of the connection verification unit the synchronization input of which is the synchronization input of the wait counter download, the output of the communication support symbol decoder is connected to the first the input of the third OR element, the second input of which is the reset input of the connection check unit.

In this device of the GigaSpaceWire communication interface, the technical result is achieved through the use of a customizable lending system that eliminates the loss of useful bandwidth both in the case of an increase in the frequency of the device and a corresponding increase in bit rate in the interface up to 1 Gb / s and higher, and with an increase in length communication channel. Adding a mechanism for setting variable parameters provides flexible adjustment of the data flow control mode adopted in the SpaceWire standard for various situations, which allows you to eliminate the problems of the lending system and eliminate the drop in useful bandwidth in the GigaSpaceWire communication interface. Changing the state machine that determines the operation of the device at the exchange level makes it possible to reduce the recovery time of the connection in the GigaSpaceWire communication interface in the reset state, which also helps to increase its throughput.

In detail, the essence of this technical solution is illustrated by the description with reference to the drawings, where in FIG. 1 shows a block diagram of a device. In FIG. 2 and FIG. 3 - presents possible options for the implementation of functional schemes of the data output unit and the data reception unit. In FIG. 4 is a functional diagram of a data flow control unit; FIG. 5 is a functional diagram of a control unit, in FIG. 6 is a functional block diagram of the connection check. In FIG. 7 shows a state machine of the physical signal exchange layer (PHY). In FIG. 8 is a timing chart illustrating a character alignment procedure 10b. In FIG. 9 shows an automaton of adaptation level of SpaceWire. In FIG. 10 is a timing diagram illustrating the transmission of a special communication support symbol SOMMA among other symbols. In FIG. 11 is a state machine graph describing the operating modes of the GigaSpaceWire communication interface device at the exchange level. In FIG. 12 shows timing diagrams of the transmission of packet data bytes; FIG. 13 is a timing chart for receiving data symbols, control symbols, and control codes; FIG. 14 are timing diagrams of transmitting a control code; FIG. 15 is a timing diagram of the transmission of a control code and a special character COMMMA communication support. In FIG. 16 shows timing diagrams of recording parameter values (constants) for setting device blocks.

As shown in FIG. 1, the proposed device comprises a data output unit 1, a data reception unit 2, a data flow control unit 3, a control unit 4, a transmit symbol 5 transducer, a symbol transceiver unit 6, a received symbol transducer 7, a connection check unit 8, a decoder 9, a register 10 parameter, input 11 allows selection of the system interface, information input 12 of the system interface, input 13 of the synchronization of the system interface, input 14 of the reset of the system interface, output 15, readiness for issuing system interface data, input 16 data recording of the system interface, input 17 of data for issuing the system interface, output 18 of readiness of the received data of the system interface, output 19 of the received data of the system interface, input 20 of reading data of the system interface, output 21 of readiness for issuing the control code of the system interface, input 22 of the recording of the control code a system interface, an input 23 of a control code for issuing a system interface, an output 24 of readiness of a received control code of a system interface, an output of 25 a received control code of a system interface face, input 26 for reading the control code of the system interface, output 27 for establishing a connection for the system interface, output 28 for errors in disconnecting the system interface, output 29 for encoding errors for the system interface symbol, output 30 for errors in crediting the system interface, output 31 for acknowledging the receipt of the flow control symbol, output 32 for confirming receiving an information symbol, output 33 of a request for issuing a flow control symbol, first reset output 34, second reset output 35, third reset output 36, symbol output ready 37 la flow control, output 38 permits the transmission of a flow control symbol, output 39 confirms the issuance of an information symbol, output 40 permits the reception of data, output 41 permits the issuance of data, information output 42, output 43 type of character, output 44 of the readiness for issuing a character, output 45 of a special character , output 46 character 8b, output 47 parameter register, output 48 local synchronization, output 49 bit signals of the communication interface, input 50 bit signals of the communication interface, input 51 of the write permission of the system parameter interface, reception synchronization output 52, connection sign output 53, symbol 8b output 54, “NULL received” output 55, special character sign output 56, encoding error output 57, information output 58, special character sign output 59, disconnect error output 60, output 61 to establish a connection, information output 62, received symbol type output 63, first enable output of the decoder 117, second enable output of the decoder 118, third enable output of the decoder 119.

The data issuing unit 1 (see FIG. 2) contains a character issuing arbitration unit 64, a data issuing buffer 65, a control code issuing register 66, a data multiplexer 67, a reset input 68, an output authorization input 69, an output synchronization input 70, a request input 71 for issuing a flow control symbol, input 72 for transmitting a flow control symbol, input 73 ready, output 74 data ready, output 75 read data, output 76 sign of the end of the packet, output 77 data, output 78 read control code, output 79 information selection, output 80 ready control code , control code output 81, synchronization input 13, data output ready 15 output, record 16 input, data input 17 for output, control code output ready 21 input, control code entry 22, control code input 23 for output, output ready 37 flow control symbol, information symbol output confirmation output 39, information output 42, symbol type output 43.

The data receiving unit 2 (see Fig. 3) contains a transformed code decoder 82, a data receiving buffer 83, a control code receiving register 84, an information input 85, a symbol type input 86, a reset input 87, a local synchronization input 88, a control selection output 89 code, output 55 "Received NULL", input 13 of synchronization, output 18 of readiness for received data, output 19 of received data, input 20 of data reading, output 24 of readiness of the received control code, output 25 of the received control code, input 26 of reading the control code, output 31 acknowledgment Lenia stream 32 output the acknowledgment information symbol, yield 40 permits the data reception.

The data flow control unit 3 contains (see Fig. 4) a credit request generator 90, a received character counter 91, a transmitted character counter 92, a credit error detector 93, a first constant register 120, a second constant register 121, a comparator 122, an input permission 94 data input 95 reset, input 96 ready to issue a flow control symbol, input 97 acknowledgment of receipt of an information symbol, input 98 confirmation of receipt of a flow control symbol, input 99 confirmation of the issuance of an information symbol, output 100 count a, exit 101 of a credit of admission, output 102 of the state, input 123 of the record, input 124 of the parameter, output 133 of the shaper of credit requests, output 134 of the comparator, output 135 of the register of the first constant, output 136 of the register of the second constant, line 137 of the record of the first constant, line 138 recording the second constant, synchronization input 13, credit error output 26, output 33 of a request for issuing a flow control symbol, output 41 of permission to issue data.

The control unit 4 contains (see FIG. 5) a state register 103, a new state generating unit 104, a control signal generator 105, a connection counter 106, a delay constant register 125, a matching circuit 126, a connection establishment input 107, a credit error input 108, an input 109 disconnection errors, input 110 symbol encoding errors, input 111 acknowledgment of receipt of the flow control symbol, input 112 acknowledgment of receipt of the information symbol, input 113 local synchronization, status output 114, status control output 115, control output 116, output 127 of the connection counter, information output 128, output 129 of the match circuit, input 130 of the record, input 131 of the parameter, input 132 “Received NULL”, input 13 of the synchronization, input 14 of the reset, output 27 of the connection, output 28 of the error of disconnection, output 29 character encoding errors, first reset output 34, second reset output 35, third reset output 36, output of the flow control symbol transmit permission 38.

Connection check unit 8 (see FIG. 6) contains a communication support symbol decoder 141, a communication setup trigger 142, a second counter 143, a first OR element 144, a second OR element 145, an AND element 146, a disconnection parameter register 147, a third OR element 148 , information input 149, input 150 of the special character sign, input 151 of the sign of the connection, input 152 reception synchronization, input 153 records, input 154 parameters, output 155 select communication support symbol, output 156 transfer, output 157 sign disconnection, output 158 register disconnect parameter, output 159 of the third ale Entry OR, reset input 160, disconnect error output 60, connection establishment output 61.

On the time diagrams (see Fig. 8) for the process of aligning the symbols in the device it is shown: a - values of bit signals, b - sign of the connection at the output 53 of the transceiver 6 characters, c - clock signals at the output 52 of the synchronization of the reception of data bits of the transceiver 6 characters, d - aligned after receiving the bits of the characters 10b in the transceiver 6 characters.

The time charts (see Fig. 10) for the transmission process of the special communication support symbol show: a - clock signals, b - data after buffering in the transmitter 5 transmitted symbols, c - code of the type of symbol after buffering in the converter 5 transmitted symbols, d - signal issuing the SOMMA special symbol generated in the converter 5, e is the data at the output of the converter 46 of the transmitted symbols 5, f is the sign of the special symbol at the output of the converter 5 of the transmitted symbols 5, g is the recording ready signal at the output of the converter 5 characters.

The time diagrams (see Fig. 12) for the process of transferring bytes of packet data to the transmit symbol converter 5 show: a - clock signals, b - data after buffering in the transmit symbol 5, c - symbol type code after buffering in the transmit 5 converter characters, d - data at the output 46 of the converter 5 of transmitted symbols, e - sign of a special character generated by the ROM of the converter 5 of transmitted symbols, f - readiness signal for writing at the output 44 of the converter 5 of transmitted symbols.

The time diagrams (see Fig. 13) for the process of receiving symbols 8b show: a - clock signals, b - data at the information output of the symbol transceiver 58, c - sign of a special symbol at the output of the symbol transceiver 59, d - symbol type code generated by ROM converter 7 of received symbols, e - data at information output 62 of converter 7 of received symbols, f - code of type of symbol delayed by a clock in converter 7 of received symbols, g - sign of a control code generated by ROM of converter 7 of received symbols s, h is the internal flag of the control code of the transducer 7 of the received symbols, i is the code of the symbol type at the output 63 of the transducer 7 of the received symbols.

The time diagrams (see Fig. 14) for the control code transmission process show: a - clock signals, b - data after buffering in the transmitted symbol converter 5, c - symbol type code after buffering in the transmitted symbol converter 5, d - data on the output 46 of the transducer 5 of transmitted symbols, e is a sign of a special character at the output 45 of the transducer 5 of transmitted symbols, f is the recording ready signal at the output 44 of the transducer 5 of transmitted symbols.

The time diagrams (see Fig. 15) for the process of transmitting a control code and a special symbol for communication support show: a - clock signals, b - data after buffering in the transmitter 5 of transmitted symbols, c - code of the type of symbol after buffering in the converter 5 of transmitted symbols, d - signal outputting the SOMMA special symbol generated in the converter 5, e - data at the output 46 of the converter 5 of transmitted symbols, f - sign of the special symbol at the output 45 of the converter 5 of transmitted symbols, g - signal of recording readiness at the output of 44 transform Vatel 5 of transmitted symbols.

In the time diagrams (see Fig. 16) for the process of recording the parameter value for adjusting the device blocks, it is shown: a - clock signals, b - data at the information input 12 of the device system interface, c - signal at the input 51 of the write permission of the system interface parameter, d is the parameter value at the output of the 47 parameter register, e is the signal at input 11 the resolution of the selection of the system interface, f is the selection signal at one of the three enable outputs 117, 118 or 119 of the decoder 9, g is the parameter value (constant) loaded into one of registers block 3, 4 or 12.

The data output unit 1 is intended for generating SpaceWire data symbols from the packet data coming through the data input for output connected to the input 17 of the device system interface of the same name, as well as control characters on demand from the output 33 of the request for issuing the flow control symbol of the control unit 3 the data stream to the input of the same name of the block 1. The input 16 of the data recording of the system interface of the device is the same input of the block 1 of data output, output 15 of the readiness of the data output of which is the same ennym output device interface system. Output 15 and input 16 of the system interface are designed to implement the standard mechanism for buffering packet data from the host system (computer, switch, or other SpaceWire network node) in the data output unit 1. The input 22 of the control code entry of the system interface of the device is the input of the data output unit 1 of the same name, the output 21 of which the control code is issued is the same name as the output of the system interface. The input 23 of the control code for issuing the system interface of the device is connected to the input of the unit of the same name 1. The recording of bytes of packet data and control codes in block 1 is clocked from its synchronization input connected to the synchronization input 13 of the device’s system interface. The outputs 37 of the readiness for issuing a flow control symbol and 39 for confirming the issuance of an information symbol of block 1 are connected to the inputs of the data flow control block 3 of the same name and are intended to implement the lending mechanism necessary to organize the transmission and reception of data through a communication interface without overflowing the receive buffers of interacting devices. The information output 42 of block 1 is connected to the data input of the transmitter 5 transmitted characters and provide the transmission of bytes of packet data and control codes. The output 43 of the symbol type of block 1 is connected to the input of the transmitter of the transmitted symbols 5 of the same name and is intended to determine the type of transmitted symbol of SpaceWire.

The data receiving unit 2 provides receiving SpaceWire characters and control codes from a remote device, buffering bytes of packet data and control codes. The output 19 of the received data of block 2 is the same output of the system interface of the device and provides the issuance of bytes of buffered packet data to the host system. The output 18 of the readiness of the received data of block 2 is the same output of the system interface of the device, the input 20 of the data reading of which is the same input of the block 2 of data reception. The output 40 of the permission to receive data of block 2, connected to the same input of the block 3 control the data flow, is designed to notify the presence of sufficient free space in the buffer 83 for receiving data. The output 25 of the received control code of block 2 is the same output of the system interface of the device and provides the issuance of the control code to the host system. The output 24 of the readiness of the received control code of block 2 is the same output of the system interface of the device, the input 26 of reading the control code of which is the same input of the block 2 of data reception. The data receiving unit 2 provides a notification to the data flow control unit 3 and the control unit 4 through the output 31 of the flow control symbol reception connected to the inputs of the same blocks 3 and 4, about the reception of the control symbol of the flow control and through the information acknowledgment output 32 connected to the same name the inputs of blocks 3 and 4, about receiving an information symbol from a remote device. The output 55 "Received NULL" of block 2 is connected to the input of the same block 4 control.

The data flow control unit 3 is designed to implement the lending mechanism required when exchanging packet data in duplex mode between two devices via a communication interface, taking into account the limited amount of buffer memory for receiving data available for each device in the data receiving unit 2. The output 33 of the request for the issuance of a flow control symbol of block 3 connected to the same input of the data output block 1 is intended to initialize the issuance by the block 1 of a flow control control symbol confirming the presence in the data reception block 2 of the free buffer space necessary for receiving a certain number of data symbols. In the described device, the amount of credit provided when one flow control symbol is issued is determined by the value of the FCT_count constant, which is set programmatically. The output 26 of the credit error of the data flow control unit 3 is connected to the input of the control unit 4 of the same name and is the output of the device system interface of the same name. The data flow control unit 3 is clocked from the synchronization input connected to the synchronization input 13 of the device system interface.

The control unit 4 is designed to monitor the status of the device when signals from SpaceWire are extracted from the received converted code from the received unit 2 and generate control signals under the influence of the state machine and the initial setting signal from the reset input connected to the reset input 14 of the device system interface. The output 38 of the permission to transmit the flow control symbol of the control unit 4 is connected to the input of the data output unit 1 of the same name and is intended to inform that the state machine of the unit 4 has switched to a mode allowing the output of flow control symbols. The first 34 reset output of the control unit 4 is connected to the reset inputs of the data output unit 1, the transmitter 5 of the transmitted characters and the transceiver 6 characters. The second 35 reset output of the control unit 4 is connected to the reset inputs of the data receiving unit 2 and the connection check unit 8. The third reset output 36 of the control unit 4 is connected to the reset input of the data flow control unit 3. Reset signals are designed to set the respective blocks in the initial state. The output 27 of the connection establishment of block 4 is the same output of the system interface of the device and is intended to inform the host system about this event. The output 28 of the disconnect error of block 4 is the same output of the system interface of the device and is intended to inform the host system about this event. The output 29 of the credit error of block 4 is the same output of the system interface of the device and is intended to inform the host system about this event. The clock when generating the status signals of the control unit 4 is carried out from the synchronization input connected to the synchronization input 13 of the system interface of the device.

Transmitter 5 for transmitting characters is intended for transcoding SpaceWire characters and control codes into 8b characters. The output 46 of the symbol 8b of the converter 5 is connected to the information input of the transceiver 6 symbols and is intended to transmit an eight-bit symbol code 8b, which corresponds to either a data byte or the code of a special control symbol. The output 45 of the character of the special symbol of the transducer 5 is connected to the input of the character type of the symbol of the transceiver 6 characters and identifies what type of character 8b is output from the output 46 of the transducer 5 in the current clock cycle (data byte or special control symbol). The output 44 of the readiness for issuing the symbol of the converter 5 is connected to the readiness input of the data output unit 1 and provides an indication of the state of readiness of the converter 5 for the arrival of the next SpaceWire symbol or control code from the data output unit 1. If the ready signal is “0”, then the converter 5 in the current cycle does not read information from block 1, since it is busy generating an additional symbol 8b in accordance with its functioning algorithm. The rules for generating special characters codes at the outputs of the transmitter 5 of transmitted characters can be implemented using eight-bit constants written in the internal ROM and defining special control characters when encoding characters 8b, which are used in this technical solution to encode SpaceWire control characters and control codes of various types. A possible implementation of these rules based on ROM constants is shown in Table. one.

A 6-character transceiver is designed to convert eight-bit characters into 10-bit characters of the 8b / 10b standard and provides a 10-bit code in each local clock cycle. The output of 49 bit signals of the transceiver 6 characters is intended for the serial transmission of bit signals generated 10-bit characters of format 10b in the communication channel of the device. The output 48 of the local synchronization of the transceiver 6 characters connected to the same inputs of the block 1 of the data output, block 2 of the data reception unit 4 of the control unit 5, the transmitter 5 of the transmitted characters, and the Converter 7 of the received characters. The input of 50 bit signals of the transceiver 6 characters, which is the input of the communication interface of the device, is designed to receive the input stream of bit signals, the formation of a parallel character code format 10b and subsequent conversion to a parallel character code format 8b. The output 54 of the symbol 8b is connected to the information input of the connection verification unit 8. The receive synchronization output 52 of the transceiver 6 is connected to the receive synchronization input of the connection check unit 8. The output 53 of the sign of the connection of the transceiver 6 characters is designed to generate a single signal when highlighting in the stream of received bit signals one of the special control characters - a communication check symbol and is connected to the inputs of the converter of the received symbols 7 and the connection checking unit 8. The output 56 of the special symbol sign of the transceiver 6 is connected to the input of the connection checking unit 8 of the same name and determines what type of symbol 8b (data byte or special control symbol) is issued from output 54 in the current clock cycle. The output 57 of the coding error of the transceiver 6 is connected to the same input of the control unit 4 and notifies the detection of errors when decoding symbols 10b. The information output 58 of the transceiver 6 is connected to the same input of the transducer 7 of the received symbols and provides the output after buffering an eight-bit code of the symbol in the 8b format at the local synchronization frequency. The output 59 of the sign of the special symbol of the transceiver 6 is connected to the same input of the transducer 7 of the received symbols and determines which symbol (data byte or special control symbol) is read from the information output 58.

Converter 7 received characters is designed to transcode 8b format characters into internal codes of character types of the standard SpaceWire. The information output 62 of the converter 7 is connected to the input of the data receiving unit 2 of the same name and provides the transmission of SpaceWire symbols and control codes received from the remote device into it. The output 63 of the symbol type of the converter 7 is connected to the input of the data receiving unit 2 of the same name and is intended to identify the type of SpaceWire symbol or control code set at the information output 62 in the current clock cycle. The rules for generating codes of SpaceWire character types can be implemented in the converter 7 of the received characters using four-bit constants recorded in the internal ROM. A possible implementation of these rules based on ROM constants is shown in Table. 2.

The connection verification unit 8 monitors the state of the connection between the remote devices during their interaction by monitoring the intervals between the arrival of a special control symbol - the communication support symbol (Comma). The output 60 of the disconnection error of block 8 is connected to the same input of the control unit 4 and provides a single signal about the connection failure when the Comma symbol timed out. The output 61 of the connection block 8 is connected to the same input of the control unit 4 and provides the formation of a signal of readiness for receiving aligned characters 10b / 8b.

The decoder 9 provides the formation at one of its outputs a selection signal that allows the parameter to be set to configure the operation mode of one of the blocks 3, 4 or 8, in accordance with the binary code on its address input, which is the information input 12 of the device’s system interface, if there is an enable signal at its control input, which is the input 11 of the resolution of the selection of the system interface of the device. The first enable output 117 of the decoder 9 is connected to the recording input of the data flow control unit 3, the second enable output 118 of the decoder 9 is connected to the write input of the control unit 4, the third enable output 119 of the decoder 9 is connected to the write input of the connection verification unit 8.

The register 10 of the parameter is intended for buffering the settings of the operating modes of the device blocks by the clock signal at its synchronization input connected to the input 13 of the same system interface of the device and in the presence of an enable signal at its control input. The control input of the register 10 of the parameter is connected to the input 51 of the write permission parameter of the system interface of the device. The information input of the parameter register 10 is connected to the information input 12 of the device system interface. The output 47 of the parameter register 10 is connected to the parameter inputs of the data flow control unit 3, control unit 4 and connection check unit 8.

In the data output unit 1, the data output buffer 65 (see FIG. 2) is intended for intermediate storage of packet data arriving at the data input for the output of the buffer 65 connected to the input 17 of the data output unit 1 of the same name. The output 15 of readiness for data output of the buffer 65 is the output of the data output unit 1 of the same name and is intended to notify the host system via the system interface of the possibility of buffering the next byte of data, which is carried out when the write signal is sent to the write input of the buffer 65, which is the input 16 of the write output block 1 data. Data buffering is provided when clocking from the synchronization input of the buffer 65 connected to the synchronization input 13 of the data output unit 1. The reset input 68 of the data output unit 1 is connected to the reset input of the data output buffer 65 and is intended for its initialization. The presentation of information in the data packet coming from the system interface of the device in the buffer 65 data output is shown in table. 3.

The reading of the buffered packet data is provided from the data output 77 of the data output buffer 65 connected to the first information input of the data multiplexer 67. The data readiness output 74 of the buffer 65 is connected to the input of the symbol issuing arbitration unit 64 of the same name and is intended to notify of the presence of a data byte ready for issuing. The output 76 of the sign of the end of the packet buffer 65 is connected to the same input of the block 64 arbitration character issuance and is intended to indicate that the previous byte was the last in the packet.

The register 66 of the issuance of the control code is designed for intermediate storage of the control code received at the input of the control code for issuing, connected to the same input 23 of the block 1 of the data output. The output 21 of the readiness for issuing the control code of the register 66 is the output of the data output unit 1 of the same name and is intended to notify the host system via the system interface of the possibility of issuing the next control code, which is performed by applying a write signal to the input of the register register 66 connected to the input 16 of the block record 1 data output. The memorization of the control code is provided when clocking from the synchronization input of the register 66 connected to the synchronization input 13 of the data output unit 1. The control code entering the device from the host system contains two fields: a control code type field and a control code value field. In the type field of the control code, it is indicated for the transmission of which specific system control signal the control code is used, for example, a time stamp or a system interrupt signal. The control code value field contains a specific parameter characterizing the meaning of the transmitted system control signal, for example, the value of the current system time or the vector of a specific interrupt. The reset input 68 of the data output unit 1 is connected to the reset input of the data output register 66 and is intended for its initialization. The reading of the recorded control code is provided from the output 81 of the control code of the register 66 connected to the second information input of the data multiplexer 67. The output 80 of the readiness of the control code of the register 66 is connected to the same input of the block 64 of the arbitration of the issuance of characters and is designed to notify the presence of a control code, ready for issuance.

The block 64 of the arbitration of the issuance of characters is designed to regulate the formation and order of issuance of data characters and control characters defined by the SpaceWire standard, according to the requirements of block 3 control the flow of data and control codes as they arrive and depending on the given priority. The SpaceWire symbols transmitted by the device through the communication interface are divided into channel and information symbols. Information symbols include the data symbol (Nchar), the end of packet symbol (EOP), and the erroneous packet termination symbol (EEP). Channel symbols are designed to control the state of the communication channel and, unlike information symbols, are not transmitted to the system interface. Channel symbols include the flow control symbol (FCT) and the null symbol (NULL code). The FCT symbol is used to implement a lending mechanism when transferring packet data between devices interacting via a communication channel. NULL code is designed to preserve the activity of the communication channel and should be constantly transmitted if the channel is not busy transmitting other characters. From the input 71 of the request for the issuance of the flow control symbol of the data output unit 1 connected to the input of the same name of the block 64, a request is issued to issue a flow control control symbol. The output 75 of reading data block 64 arbitration character issuance, connected to the input of the same name of the buffer 65 of the data output, is designed to control the rate of receipt of data from the buffer 65 to generate the internal code of the data characters in block 64. The output 78 of reading the control code of the block 64, connected to the same input register 66 control codes, designed to control the rate of issuing control codes from the output 81 of register 66. The internal coding of the characters generated in the block 64 is shown in Table. four.

An input 72 for permitting the transmission of a flow control symbol of the data issuing unit 1, which is the same input of the symbol issuing arbitration unit 64, is intended for the initial authorization of issuing FCT symbols after establishing a connection with a remote device. The readiness output 37 for issuing a flow control symbol of block 64, which is the same output of the data output unit 1, is intended to notify the flow control unit 3 of the possibility of issuing another FCT symbol. The output 39 of the confirmation of the issuance of the information symbol, which is the same output of the data output unit 1, is intended to notify the flow control unit 3 of the issuance of the next Nchar symbol in order to manage the credit counter of 92 transmitted symbols. The output 43 of the symbol type of the block 64 of the arbitration of the issuance of characters, which is the same output of the unit 1 of the data output, is intended for identification in accordance with the encoding given in Table 2, a symbol or control code transmitted through a data multiplexer 67. The information selection output 79 of the unit 64, connected to the control input of the data multiplexer 67, provides a choice of the information source for transmission through the multiplexer 67. When the selection signal is zero, the data byte from the data output buffer 65 is supplied to the information output 42 of the multiplexer 67 from the first information input; at a single value of the selection signal, a control code is supplied from the second information input to the information output 42 of the multiplexer 67 from the buffer 66 for issuing control codes. Thus, as shown in the table. 2, the type of the data symbol or control code at the output 43 is accompanied by the data byte itself at the output 42 of the symbol output unit 1. The clocking of the block 64 arbitration of the issuance of characters is carried out from the synchronization input connected to the synchronization input 13 of the data output unit 1, the reset input 68 of which is connected to the reset input of the block 64 and is intended for its initialization. The information output 42 of the data multiplexer 67 is the same output of the data output unit 1.

In the data receiving unit 2, the transformed code decoder 82 (see Fig. 3) of the code is intended for character recognition and control codes of the SpaceWire network in accordance with the encoding shown in Table. 3, and generating control signals necessary for buffering received packet data and control codes, as well as changing the state of data flow control units 3 and 4 control units. The information input of the decoder 82 is an input 86 of a symbol type of the data receiving unit 2. The output 32 of the acknowledgment of the information symbol of the decoder 82, which is the same output of the data reception unit 2 and connected to the write enable input of the data reception buffer 83, is intended to generate a single signal in one of the following two options: either when receiving the Nchar data symbol or when receiving end of package (EOP). The output 89 of the selection of the control code of the decoder 82, connected to the write enable input of the buffer 84 receiving control codes, generates a single signal confirming the receipt of the control code. The output 31 of the acknowledgment of receipt of the symbol of the flow control, which is the same output of the data receiving unit 2, is intended to provide a sign of acknowledgment of receipt of the FCT symbol, necessary for the operation of the lending mechanism when controlling the flow of data from this device to the remote. The output 55 "Received NULL" of the decoder 82, which is the same output of the data receiving unit 2, generates a single signal confirming the receipt of the NULL code.

The data reception buffer 83 is intended for intermediate storage of received data packets arriving at its information input from the same input 85 of the data receiving unit 2, in the presence of a single signal at the recording permission input. At the output 19 of the received data of the buffer 83, which is the output of the data receiving unit 2 of the same name, a byte output of data packets separated by signs of the end of the packet is provided. The data output from the data reception buffer 83 is ensured according to the “first received, first read” (FIFO) principle, accompanied by a data ready signal at the received data readiness output 18, which is the output of the data receiving unit 2 of the same name, and if there is a single signal at the buffer data read input 83, which is a data reading input 20 of a data receiving unit 2. The output 40 of the permission to receive data of the buffer 83, which is the same output of the data receiving unit 2, indicates the presence of a certain number of free cells in it (in the described embodiment, at least eight) and is intended to control the lending mechanism. When data is written to the data reception buffer 83, it is clocked on the rising edge of the clock signal from the first synchronization input connected to the local synchronization input 88 of the data receiving unit 2. When reading data, the buffer 83 is clocked from the second synchronization input connected to the synchronization input 13 of the data receiving unit 2 and is initialized by the signal from the reset input connected to the reset input 87 of the data receiving unit 2.

The control code reception register 84 is intended for intermediate storage of the received control code received at its information input from the information input 85 of the data receiving unit 2, if there is a corresponding single signal at the recording permission input. At the output 25 of the received control code of the register 84, which is the same output of the data receiving unit 2, the control code is provided. Reading the control code from the register 84 is accompanied by a single ready signal at the ready output 24 of the received control code, which is the output of the data receiving unit 2 of the same name, and if there is a single signal at the read input of the control code of the register 84, which is the same input 26 of the data receiving unit 2. When writing the control code, the control code reception register 84 is clocked on the rising edge of the clock signal from the first synchronization input of the register 84 connected to the local synchronization input 88 of the data receiving unit 2. When reading the control code, register 84 is clocked from the second synchronization input connected to the synchronization input 13 of the data receiving unit 2 and is transferred to the initial state by a signal from the reset input connected to the reset input 87 of the data receiving unit 2.

In the data flow control unit 3 (see Fig. 4), the credit request generator 90 is designed to generate an FCT symbol request signal at the output 33 of the request for issuing the flow control symbol of block 3 in the presence of enable signals at the readiness inputs 96 of the flow control symbol and 94 permission to receive data of block 3 and depending on the status of the counter 91 received characters. The input 3 for data reception of block 3 is the first input of the shaper 90. The input 96 of the readiness for issuing the flow control symbol of block 3 is the second input of the shaper 90. The state output 100 of the counter of the received symbols 91 is connected to the third input of the shaper 90. The synchronization input 13 of the block 3 connected to the synchronization inputs of the credit request generator 90, the counter 91 received characters, the counter 92 transmitted characters and the detector 93 credit errors, provides synchronization of their work at the frequency of the system interface. The reset input 95 of block 3 is used to set the initial state and is connected to the reset inputs of the credit request generator 90, the received character counter 91, the transmitted character counter 92 and the credit error detector 93, the first constant register 120 and the second constant register 121. The counter 91 of the received symbols provides the formation of a binary code that determines the number of information symbols that are allowed to be received in this device. The first control input of the counter 91, connected to the output 133 of the credit request generator 90, is designed to load the counter constant FCT_count from its information input into the counter 91 when generating a request signal for the flow control symbol. Register 120 of the first costant is designed to store the value of the constant FCT_count, which determines the amount of credit when transmitting information symbols between interacting parties. The information input of the register 120 is connected to the input 124 of the parameter of the block 3. The input 123 of the record of the block 3 includes the line 137 of the recording of the first constant connected to the input of the record of the register 120 of the first constant and recording the constant FCT_count into it by the clock signal from the block synchronization input 13 3 to the input of the synchronization register 120. The output 135 of the register 120 of the first constant is connected to the information input of the counter 91 of the received symbols. The second control input of the counter 91, which is the input 97 of the acknowledgment of the information symbol of block 3, is designed to reduce the content of the counter 91 by one when each information symbol is received from another device. The state of the counter 91 of the received symbols under the influence of control signals is changed along the edge of the clock signals from the synchronization input 13 of block 3 to the synchronization input of the counter 91. The output 101 of the credit error of the reception of the counter 91 is connected to the first information input of the credit error detector 93 and is designed to generate an error signal when trying to reduce the state of the counter below the maximum permissible value. The counter 92 transmitted characters provides the formation of a binary code that determines the number of information characters that are allowed to transmit from this device. The first control input of the counter 92, which is the input 98 of the acknowledgment of the flow control symbol of block 3, is designed to enable the calculation of the transmitted information symbols in the counter 92 upon receipt of each FCT symbol. The second control input of the counter 92, which is the input 99 of the confirmation of the issuance of the information symbol of block 3, is intended to increase by one the contents of the counter 92 of the transmitted characters. Changing the state of the counter 92 transmitted characters when applying control signals is carried out on the front of the clock signals from the synchronization input 13 of block 3 to the synchronization input of the counter 92. The counter status output 102 is connected to the second information input of the credit error detector 93 and the first input of the comparator 122.

The credit error detector 93 provides the formation of a combined clock error signal of the credit error at its first output, which is the output 26 of the credit error of block 3, or the data enable signal at its second output, which is the output 41 of the output of data from block 3. The synchronization input of the detector 93 is connected to the input 13 synchronization unit 3 control the flow of data. The register 121 of the second constant is designed to store the value of the constant Max_Fct_count, which determines the maximum amount of credit when issuing information symbols. The information input of the register 121 of the second constant is connected to the input 124 of the parameter of the block 3. The input 123 of the record of the block 3 includes a line 138 of the recording of the second constant connected to the input of the record of the register 121 and recording the constant Max_FCT_count into it according to the clock signal from the block synchronization input 13 3 to the input of the synchronization register 121. The output 136 of the register 121 of the second constant is connected to the second input of the comparator 122, which is designed to generate an error signal when trying to increase the state of the counter 92 above the maximum allowable of the value determined Max_Fct_count constant value. The output 134 of the comparator 122 is connected to the input of the error flag of the credit error detector 93.

In the control unit 4 (see Fig. 5) that implements the state machine, the state register 103 is designed for online storage and monitoring of the state of the phases of the device. In fact, the state register 103 is the memory of the state machine, which is implemented by the control unit 4. Register 103 can be read as well as writable by the host system (not shown in FIG. 5). Filling the register is performed bitwise by signals from the block 2 of the data reception or processor of the host system. The state output 114 of the register 103 is connected to the first control input of the new state generating unit 104 and to the control input of the control signal generator 105. The connection establishment output 27 of the status register 103 is the same output of the control unit 4. A single signal value at this output indicates a connection at the SpaceWire standard exchange level. The output 28 of the error of disconnection of the state register 103 is the same output of the control unit 4. A single signal value at this output indicates a connection error when exchanging data between remote devices. The output 28 of the credit error of the state register 103 is the same output of the control unit 4. A single signal value at this output indicates a credit error when exchanging data between remote devices. The reset input 14 of the control unit 4 is designed to set the initial state and is connected to the reset inputs of the state register 103, the driver 210 of the control signals and the block 106 delay. The recording of status bits in the register 103 is provided on the rising edge of the clock signal at its synchronization input, which is the synchronization input 13 of the control unit 4. Block 104 of the formation of a new state is designed to implement the logic of the state machine, which performs the function of an automaton that transitions under the influence of input signals to various states. The control signal generator 105 provides the generation of control signals by which the state machine transfers the data output unit 1, the data reception unit 2, the data flow control unit 3, and the connection verification unit 8 to the initial states, thus allowing the correct operation of the device as a whole. Connection counter 106 is designed to generate timeouts necessary for the state machine to function correctly when establishing and maintaining a connection with a remote party through a communication interface. To implement the state machine graph shown in FIG. 11 requires the need for the formation of several timeouts. The local synchronization input 113 of the control unit 4 is connected to the synchronization inputs of the control signal generator 105 and the connection counter 106. The connection establishment input 107 of the control unit 4 is the first input of the new state generating unit 104. Block 108 credit error input 108 is the second input of block 104. Block 4 disconnect error input 109 is the third input of block 104. Block 4 character encoding error input 110 is the fourth input of block 104. Block 4 flow control acknowledgment input 111 is the fifth block input 104. The input 112 for acknowledging the information symbol of block 4 is the sixth input of block 104. The input 132 “Received NULL” is the seventh input of the new state generating unit 104, the output 115 of which is connected to the recording input of the status bits histra 103 state. The control output 116 of the control signal generator 105 is connected to the control input of the connection counter 106, the output of which 127 is connected to the second input of the coincidence circuit 126, the first input of which is connected to the output 128 of the delay constant register 125. The match circuit 126 is intended to generate a timeout completion signal at its output 129, which is connected to the second control input of the new state generating unit 104. The output 38 of the resolution of the transmission of the symbol of the flow control of the driver 105 of the control signals is the same output of the control unit 4. The first output 34 of the reset of the driver 105 is the same output of the unit 4. The second output 35 of the reset of the driver 82 is the same output of the unit 4. The third output 36 of the reset of the driver 82 is the same output of the control unit 4.

In block 8 of the connection check (see Fig. 6), the communication support symbol decoder 141 selects the Comma communication support symbol by generating a single signal at its output 155, which is connected to the first input of the third OR element 148 and to the first input of the first OR element 144, the output of which is connected to the data input of the trigger 142 communication. The enable input of the decoder 141 is connected to the input 151 of the sign of connection of block 8, with the inverse input of the reset trigger 142 of the communication and with the first inverse input of the second element 145 OR. A zero level signal at this input provides a ban on the operation of the decoder 141, in which the output 155 of the decoder 141 is in a passive zero state. A single signal level of the sign of the connection activates the operation of the decoder 141. The first input of the decoder 165 is the information input 149 of block 8 and ensures that the 8-bit binary 8b symbol code enters the decoder 141. The second input of the decoder 141 is the input 150 of the special character attribute of block 8 and provides a single-bit control signal, the unit value of which sets the decoder 141 to decode the received binary code to its first input as a special control symbol. When the value of the sign of the special character is zero, the decoder 141 ignores the binary code at the first input, since this binary code is a data symbol that must be written to the data buffer in the received data converter 7. The trigger 142 connection is designed to fix the establishment of a connection in which it becomes possible to exchange data between interconnected devices, that is, each device receives permission to transmit data to a remote device. The trigger synchronization input 142 is the receive synchronization input 152 of the connection verification unit 8 and is connected to the decrement input of the standby counter 143. At a single value at the input of data on the increasing input of the clock signal, the trigger 142 for establishing communication is switched to a single state, which indicates the establishment of a connection. The connection establishment trigger of the communication setup trigger 142 is the connection establishment output 61 of the connection verification unit 8 and is connected to the second input of the first OR element 144 and to the first input of the fourth element 146 I.

The standby counter 143 is designed to monitor the time interval of the CommaTime during which a special Comma communication support symbol must be received to maintain the connection from the remote device. If the specified special control character does not arrive during the CommaTime interval, then the counter 143 provides the formation of a transfer signal, notifying of the disconnection error. The output 156 of the transfer of the counter 143 is connected to the second input of the second OR element 145, which ensures the formation of a single value of the disconnect sign in the absence of a special symbol for checking communications or in case of loss of synchronization. The output 157 of the disconnect flag of the second OR element 145 is connected to the second input of the AND element 146, which provides the formation of a single value of the disconnect error signal only if there is an established connection. The output of the fourth element 146 And is the output 60 of the disconnection error of the connection verification unit 8. The disconnection parameter register 147 is designed to store the value of the CommaTime interval, which is recorded from the information input connected to the parameter input 154 of block 8, by the enable signal at the recording input connected to the recording input 153 of block 8. The reset input 160 of block 8 is connected to the second input of the third element 148 OR, which is designed to generate a load signal of the initial value of the interval in the counter 143 wait. The input 159 of the third OR element 148 is connected to the download input of the standby counter 143. The CommaTime value from the output 158 of the disconnect parameter register 147 connected to the information input of the standby counter 143 is written to the counter 143 if there is an enable signal at the download input and a clock edge at the download synchronization input connected to the synchronization input of the connection check unit 8.

The device operates as follows. The objective of the device is to provide data exchange between a local host system (a computer or processor node having a local data memory) and a remote host system through a similar remote communication interface device. The local device and its local host system are hereinafter referred to as “Side A”, the remote communication interface device and its host system - “Side B”. To accomplish this task, this device organizes the connection in a communication channel connecting parties A and B, and provides data flow control. A communication channel supporting duplex serial data transmission mode is formed (see Fig. 1) by output 49 and input 50 by simplex bit-signal transmission lines.

The device has three levels of connection and information exchange control: the SpaceWire network exchange level, adaptation level and bit synchronization level. The state machine of each control level is represented by a state diagram (see Figs. 7, 9, and 11).

Before establishing a connection at the SpaceWire exchange level, it is necessary to establish a physical connection at the adaptation and bit synchronization levels. The state machine of the bit synchronization level, which determines the signal exchange at the physical level (PHY), is shown in FIG. 7. After the SpaceWire exchange level has allowed the PHY level to begin operation, the 6-character transceiver coding unit 8b / 10b starts sending special characters to establish bit synchronization with the receiving unit of the transceiver 6 bits of the remote device. To this end, interconnected devices send each other primary synchronization symbols of format 10b, defined as symbols D10.2. After coding at the output 49 of the transceiver 6, it has the form "1010101010". After switching on, 6 character transceivers in each of the devices send D10.2 synchronization symbols to the channel for a certain period of time. In this “Bit Sync” state, D10.2 sending continues and the codec waits for receive synchronization. After establishing the synchronization of reception, the machine switches to the “Alignment” state. To do this, the transmitter generates a special symbol Comma for communication support K28.5 in 8b format, after encoding in 10b format it has the form “1100000101”. When this symbol appears in the receiver, the data is considered aligned and parallel 10-bit sequences appear, transmitted to the overlying layer, as reflected in FIG. 8. The transceiver 6 at the output 53 sets the unit signal level of the sign of the connection. Upon receipt of this Comma symbol, the PHY level switches to the Ready state (see Fig. 7).

To organize the interaction of the physical layer of the GigaSpaceWire communication interface and the SpaceWire exchange level, the SpaceWire adaptation level is introduced, the tasks of which are:

1) encoding and decoding of SpaceWire characters into 8b characters (character sequence);

2) determination of disconnection errors;

3) coordination of the frequencies of the receiver and transmitter.

The adaptation layer is responsible for encoding SpaceWire characters into 8b characters. The adaptation level machine shown in FIG. 9, starts its work after turning on the device and in the “Reset” state, waits for synchronization of the PHY level. After the synchronization is established, the transition to the "Waiting" state is performed. After 2 microseconds, the machine of the adaptation level transitions to the “Start” state. In this state, periodic sending of special communication support Comma characters (K28.5) begins. After receiving the Comma symbol and sending at least one symbol after that, it goes to the Ready state. In this state, the conversion of 8b-characters to SpaceWire characters and vice versa is allowed, and in this way conditions are prepared for receiving the first NULL code, which is an important event for the state machine of the SpaceWire exchange level. If within a certain time a special symbol for communication support has not been received or an 8b / 10b encoding error has been detected, the transition to the "Error" state occurs. For the SpaceWire exchange level, a coding error signal is generated at the output of the 6 transceiver 6 characters, which will cause the machine to reset the SpaceWire status (at the exchange level). After that, if the underlying PHY level has not lost synchronization, a transition to the "Waiting" state is performed. If PHY level synchronization is lost, it switches to the “Reset” state.

The determination of the disconnect error that the SpaceWire exchange layer processes is the responsibility of the adaptation layer. To detect disconnection from the converter 5 of transmitted symbols, a special communication support symbol is sent through the CommaTime interval (see timing diagrams in Fig. 10), inserting it into the general symbol stream. CommaTime, the interval between the transmission of two SOMMA characters, cannot be longer than the time required to transmit 128 characters, but cannot be less than the transmission time of 8 characters. Work in the transmission time range from 8 to 32 characters should be supported in all implementations.

If an error occurs on one of the parties, this side goes into the “Error” state, and then into the “Waiting” state. In these states, the Comma special character (K28.5) is not sent. The opposite side, having not received the Comma special character for communication support for a long time (within 640 ns - 960 ns at a transmission frequency of 1 GHz), detects the disconnect error and also goes into the Error state.

The exchange level of the SpaceWire standard and higher function in accordance with the recommendations of the SpaceWire standard. Changing the states of the data output unit 1, the data receiving unit 2, the data flow control unit 3, and the control unit 4 is carried out in accordance with the state machine diagram (see Fig. 11) of the SpaceWire exchange control level: from device initialization by the initial setup signal starting from resetting one of the parties connected by a communication channel to a state of normal operation, in which packet data and control codes are transmitted in both directions. From the “Reset” state, in which the data receiving unit 2 does nothing, it goes into the “Start” state. In this state, block 2 is running and is waiting for the first bit to be received. When the data receiving unit 2 receives the first NULL code, it switches to the “Connection” mode, and the disconnection detection mechanism is turned on and only NULL codes are allowed to be received. After receiving the FCT symbol from the remote device of the communication interface, the data receiving unit 2 enters the Run state and can receive NULL codes, FCT symbols, information symbols, including Nchar data symbols and EOR / EEP packet end symbols, and control codes (UK), which transmitted over the SpaceWire network. In this state, the device includes a mechanism for detecting disconnect and coding errors.

After a reset or an error in the channel, the data output unit 1 is transferred to the “Reset” state and, when the connection is initialized at the exchange level, SpaceWire can be in one of four states:

1. Reset. The data output unit 1 does nothing.

2. Launch (Connecting). The data output unit 1 sends only NULL codes. It is not ready to transmit information symbols and does not transmit FCT symbols.

3. Connected. Transmission of FCT characters / NULL codes. The data output unit 1 sends FCT symbols or NULL codes and is not ready to transmit information symbols.

4. Run mode - the normal mode of operation of the data output unit 1 (FCT / Nchar / NULL / UK transmission). It sends FCT characters, NULL codes, information characters (Nchar / EOP) and control codes.

The control unit 4 performs the function of a control machine in the device, which is a state machine, the graph of which is presented in FIG. 11. It controls the operation of the data output unit 1, the device data reception unit 2 and the flow control unit 3, receiving status signals from them and sending them control signals. Two types of signals serve as events or conditions that cause transitions from state to state: external (for example, reset) and internal control signals. One of the determining factors affecting the performance of the device when establishing a connection after a reset and its recovery from errors is the choice of delay values. Due to the too long delays in the “Reset” state defined in the SpaceWire standard, reconnection in the GigaSpaceWire communication interface is slow, which reduces the throughput of the interface. Therefore, in this technical solution, variable values of the delays are introduced, providing flexible configuration of the device for various applications. One of the main internal control signals that cause transitions in the state machine is the delay triggering signals T.

Time T has passed - the delay signals when the connection counter 106 overflows in the control unit 4 cause time-out (time delay) transitions from one state to another. The delay values are determined by the following parameters.

- DiscDetect - time interval for which the disconnect error is determined. Must be twice as large as the CommaTime parameter.

- ResetTime - the time interval in the Reset state. Must be twice as large as DiscDetect.

- Wait_conn_Time - time interval for establishing a connection. Must be at least 8 times the CommaTime time.

Other internal control signals that cause state transitions are:

- A NULL code is received - the signal is set at the output 55 of the data receiving unit 2 (see Fig. 3) when the first NULL code is received.

- Received FCT symbol - the signal is installed at the output 31 of the acknowledgment of the reception of the flow control symbol of the data receiving unit 2 and means the fact that the FCT symbol is received. Reception of the FCT symbol is correct only in the states “Connected (Connected)) or“ Operating mode (Run) ”. Reception of the FCT symbol in other states is perceived as an error.

- Received Nchar - the signal is installed at the output 32 of the acknowledgment of the information symbol of the data receiving unit 2 and means the fact of the adoption of the information symbol. Reception of an information symbol in any state other than the Run state is perceived as an error.

- Disconnect error - the signal at the output 60 of the disconnection error of the connection check unit 8 means out of sync in the communication channel. The mechanism for determining the disconnect error in block 8 starts when, after establishing a connection, and exiting the “Reset” state.

- Encoding error - the signal at the output 57 of the encoding error of the transceiver of 6 characters means the definition of an error in the received symbol or an error due to incorrect encoding. The determination of the encoding error is allowed only when the data reception unit 2 is started and after the first NULL code is received.

- Credit error - a signal at the output 30 of a credit error of the data flow control unit 3 means that information symbols are received that are not expected (receiving an information symbol at the moment when all information symbols are already received in response to the sent FCT symbols). A credit error also occurs when an FCT symbol is received at a time when the increase in credit exceeds the maximum value of Max_FCT_Count. The value of Max_FCT_Count should be 56 when working in the SpaceWire standard mode; in the flow control mode for the GigaSpaceWire interface, the Max_FCT_Count parameter should be 512.

In addition to the internal control signals generated in the device blocks, the state machine generates the following internal conditions for transitions:

- Receive error - this condition indicates the occurrence of a disconnect error or an encoding error signal.

- Symbol sequence error - this condition is generated by the state machine differently depending on the current state:

a. Any characters received before the first NULL code are ignored. In the “Standby” and “Ready” states, this leads to an error, which causes the transition to the “Reset” state. In the state diagram (see FIG. 11), the events “Received FCT” and “Received Nchar” are indicated.

b. After receiving the first NULL code, receiving the FCT character before sending the first NULL code (that is, in the "Started" state) is perceived as an error.

c. An information symbol can be accepted only after a NULL code and FCT symbol are received, otherwise the situation is erroneous. Therefore, in the “Connected” status)), the “Received Nchar” event causes the device to reset. In this way,

information symbols can only be received in operating mode (“Run” state).

The device transmits data to the communication channel in the operating mode sequentially (see timing diagrams in Fig. 12), reading bytes of packet data from the data output buffer 66 of the data output unit 1 as they arrive from the host system. If there is a readiness to issue data in the form of a single level at the output 44 of converter 5 (see Fig. 12, f), the next data byte is read from the information output 42 of the data output unit 1 and is buffered in converter 5 (see Fig. 12, b) and it then goes to the output 46 of the symbol 8b of the converter 5 (see Fig. 12, d). In this case, the internal symbol type code equal to “001” (see Table 1) is read from the output of the symbol type of block 1, and the built-in ROM in the converter 5 forms a zero level of a special character attribute (see Fig. 12, f). The zero sign signal of the special symbol at the output 45 of the converter 5 confirms that in the transceiver 6, when performing coding 8b / 10b, the symbol 8b arriving in the current clock cycle should be interpreted as a data symbol. If the next byte of data transferred was the last in the packet, then the symbol of the end of the packet is transmitted in the next clock cycle. The EOR symbol type code is “010” (see Table 4), in accordance with it, the ROM in converter 5 forms the special symbol K28.3, and the sign of the special symbol takes a single value (see Fig. 12, diagrams d, e). The eight-bit code of this special character 8b is transmitted to the output 46 of the character 8b of the converter 5, and a unit value is present at the output 45 of the special character flag.

When the data output buffer 65 in block 1 is empty and the transmission of data bytes through the device to the other side of the connection is suspended, a NULL code is transmitted so as not to lose the synchronization of the device connection. The built-in ROM in the converter 5 in this situation forms another special character - K28.0 (see Fig. 12, diagrams b, c, d), which means the transfer of a NULL code (see table 4). Timing diagrams illustrating the process of transmitting a control code in a packet data stream are shown in FIG. 14. First, the special symbol K28.6 will be sent to the channel as the UK header, and the data symbol following it is a parameter of the control code (see Fig. 14, diagrams b, c, d). To do this, converter 5 will first output a constant byte code 46 (K28.6) from the built-in ROM together with a single sign of the special character at output 45 (see Fig. 14, d), and at the next clock step, the byte of the control code parameter read from information output 42 block 1 data output. If the transmission of the control code and the special symbol for communication support coincide, the control symbol will be transmitted first, then the communication support symbol K28.5 (see Fig. 15, diagrams b, c, d, e, f).

Received symbols of the 8b format are buffered in the 6 symbol transceiver from which they are converted into SpaceWire symbols into the received symbol converter 7. The received symbols 8b (see Fig. 4) are sent to the information input 58 of the converter 7, and the internal ROM decodes the symbols 8b into an internal code of the SpaceWire symbol type (see Table 2 and Fig. 13, d). The data byte after buffering in the converter 7 (see Fig. 13, f) is directly written from the information output 62 to the data output buffer 83 of the block 2. At the same time, the code of the type of the received data symbol from the ROM output is buffered and appears at the output of the 63 received symbol type transducer 7 (see Fig. 13, i). The converted code decoder 82 in the data receiving unit 2 recognizes the Nchar symbol, generating a single signal at the output 32 of the acknowledgment of the information symbol. If a control code is received, a single sign of the control code is generated at the output of the ROM in the converter 7 (see Fig. 13, g). This feature is fixed as a flag of the control code (see Fig. 13, h), while the code of the type of the control code is also delayed by a clock cycle (see Fig. 13, f) and then it is output to the output 63 of the type of the received symbol of the converter 7 of the received symbols ( see Fig. 13, i). At the same time, the byte of the control code parameter is issued to the information output 62 of the converter 7, which will then be transferred to the control code receiving register 84 of the data receiving unit 2.

The proposed technical solution will remove a significant part of the problems of SpaceWire technology that were solved during the development of this device of the GigaSpaceWire communication interface: it makes the maximum use of the factor of increasing the bit rate in the channel to increase the throughput in general for the GigaSpaceWire communication interface device. The ability to flexibly select and configure delay parameters in the state machine for various applications allows you to speed up the connection recovery process in the GigaSpaceWire interface. As a result of experimental studies, the following relationship between time intervals (time-outs) determining the efficiency of the GigaSpaceWire communication interface device can be recommended. If the CommaTime interval of issuing the communication support special symbol SOMMA is equal to 128 nanoseconds, then DiscDetect will be equal to 256 nanoseconds, ResetTime equal to 512 nanoseconds, Wait_conn_Time equal to 1024 nanoseconds. In this case, the fraction of the channel bandwidth used on the commune is inefficient, will be t / (128 + t), where t is the transmission time of the COMMA symbol in the channel. If the bit rate of the communication channel is 1 GHz, then the total transmission time of the COMMA symbol is 10 ns, and then t / (128 + t) = ~ 0.072, that is, 7.2% of the channel bandwidth is used inefficiently.

By reducing the frequency of sending the COMMA symbol, you can provide a large useful channel bandwidth, for this you can increase the CommaTime interval to within 1024 nanoseconds, then DiscDetect will be equal to 2048 nanoseconds, ResetTime will be equal to 4096 nanoseconds, Wait_conn_Time will be 8192 nanoseconds. Moreover, the timeout values do not depend on the speed or length of the channel. If the CommaTime interval is 1024 nanoseconds, then the inefficient use of channel bandwidth is t / (1024 + t) = ~ 0.01, which means a loss of 1% of the channel bandwidth. Thus, more than 6% increases the effective use of the useful bandwidth of the channel. For comparison, we note that in the prototype, the constant determining the number of information symbols, after the transmission of which it is necessary to issue the SOMMA special symbol, was 16 words for a specific implementation. We take as a basis the maximum channel frequency at which transmission is effective, equal to 625 MHz. Then the CommaTime interval is 320 ns. In this case, the DiscDetect disconnect time will be 640 ns; ResetTime will be 1280 ns for all cases. According to the same formula, t / (320 + t) = ~ 0.059, which corresponds to about 6% of the channel bandwidth used inefficiently. To reduce these losses in a specific implementation of the prototype there is no technical possibility.

The need to change the state machine is also dictated by the long connection time when detecting errors in the channel. In the prototype, in the initial version of the state machine, 19.2 μs was required to transition to the connection state. This is an adequate recovery time for low transmission speeds, but is absolutely unacceptable for transmission frequencies above 1 GHz, since an interval of 19.2 μs was used for the worst-case worst case with a large margin. This delay necessary to perform the procedures for reconnecting the channel can be reduced by entering an appropriate coefficient depending on the frequency of sending the COMMA symbol, as shown in the above examples. If you make a connection recovery delay, depending only on the frequency of sending the SOMMA special character, the time to establish a connection will be reduced several times, depending on the given constants.

Elimination of the credit system problems in this technical solution, which are characteristic of GigaSpaceWire communication interface devices operating at frequencies above 600 MHz in accordance with the specifications of the SpaceWire standard, allows eliminating the device’s bandwidth loss while increasing the bit rate in the channel up to 1 Gbit / s and higher. The change in the size of the loan is due to the fact that the inefficient use of the channel at high frequencies (more than 1 GHz) and channel lengths of more than 50 meters is approximately 80% in the worst case. During physical implementation of pairing with a communication channel (at the PHY level), various signal levels can be used in the device, which is reflected in a significant expansion of the scope of SpaceWire modules. The device can use LVDS according to the Serial RapidIO standards (which are fully implemented at speeds of 1 Gbit / s and more), physical channels on copper cables and fiber-optic channels. There are conditions for the use in the technical implementations of this device of proven technical solutions, for example, for galvanic isolation. From the electronic component base available on the market for PHY, signals with PECL / LV-PECL FibreChannel levels can be used, cable products and InfiniBand connectors, and other well-known technical solutions can be applied. Thus, this technical solution contributes to the achievement of higher indicators of reliability and speed, has significant functional advantages compared to well-known analogues, and is implemented using the current level of technology.

Claims (3)

1. A GigaSpaceWire communication interface device for a SpaceWire network, comprising a data output unit, a transmit symbol converter, a symbol transceiver, a received symbol converter, a data receive unit, a connection test unit, a control unit and a flow control unit, the output of the request for issuing a flow control symbol of which is connected with the input of the data output unit of the same name, the output of the readiness for issuing a flow control symbol which is connected to the input of the data flow control unit of the same name, the inputs are confirmed the reception of the flow control symbol and the acknowledgment of the information symbol which are connected respectively to the outputs of the data receiving unit and the inputs of the control unit of the same name, the output of the character encoding error of which is the output of the character encoding error of the system interface of the device, the synchronization input of which is connected to the inputs of the data output unit of the same name, a data receiving unit, a data flow control unit and a control unit, a reset input of a device system interface is an input ohm of the reset of the control unit, the first output of the reset of which is connected to the inputs of the reset of the data output unit, the converter of transmitted characters and the transceiver of characters, the second output of the reset of the control unit is connected to the reset input of the data reception unit, the output "received NULL" of which is connected to the same input of the control unit, the input of reading data from the system interface of the device is the input of the data receiving unit of the same name, the data outputs for receiving and the readiness of the data for receiving which are the corresponding outputs of the system a lot of the device interface, the credit error output of the system interface of the device is the output of the data flow control unit of the same name and is connected to the input of the control unit of the same name, the third reset output of which is connected to the reset input of the data flow control unit, whose acknowledgment information is received and the data reception permission is connected to the outputs of the same name respectively of the data output unit and the data reception unit, the output readiness output of the data of the device system interface is are the same output as the data output unit, the recording and data inputs for issuing the system interface of the device are the corresponding inputs of the data output unit, the connection error of the connection verification unit is connected to the input of the control unit of the same name, the information input of the symbol transceiver is connected to the output of the symbol 8b of the transmitter of transmitted symbols, the output the readiness for issuing a symbol of which is connected to the readiness input of a data output unit, the information output and the output of the type of symbol of which are connected respectively, with the data inputs and the symbol type of the transmitter of the transmitted characters, the output of the special character of which is connected to the input of the character type of the character of the symbol transceiver, the output of the bit signals of which is the same output as the communication interface of the device, the local synchronization output of the symbol transceiver is connected to the inputs of the transmitter of the transmitted symbols, the converter of received characters, control unit, data receiving unit and data output unit, write entry of the branching code of which is the input of the device’s system interface of the same name, the output of which is ready to issue the control code of which is the output of the data output unit of the same name, the input of the control code for the output of which is the input of the device’s system interface of the same name, the output of the received control code of which is the same output of the data receiving unit the received control code of which is the output of the same system interface of the device, the input of reading the control code which is the input of the data reception unit of the same name, the information input and the input of the symbol type of which are connected respectively to the outputs of the received symbol converter of the same name, the information input of which is connected to the same output of the symbol transceiver, the output of the symbol 8b of which is connected to the information input of the connection check unit, the input of the special character of which connected to the input of the transmitter of the received characters and the output of the transceiver of characters of the same name, the output of the encoding error which is connected to the input of the control unit of the same name, the connection establishment input of which is connected to the output of the connection verification unit of the same name, the connection attribute input of which is connected to the input of the received symbol transformer of the same name and the output of the symbol transceiver of the same name, the reception synchronization output of which is connected to the connection of the connection verification unit of the same name, the input of the bit signals of the symbol transceiver is the input of the same device communication interface, the unit The equation comprises a status register, a new state generation unit and a control signal generator, the reset input of which is a reset input of the control unit and connected to the reset inputs of the status register, the status output of which is connected to the first control input of the new state formation unit and with the control input of the control signal generator, the connection establishment output, the disconnect error output and the status register symbol encoding error output are the outputs of the control unit of the same name, the synchronization input of which is the synchronization input of the status register, the state control input of which is connected to the state control output of the new state generation unit, connection establishment inputs, credit errors, disconnection errors, symbol encoding errors, acknowledgment of receipt of the flow control symbol and acknowledgment of receipt of the information symbol of which are of the same name inputs of the control unit, the local synchronization input of which is connected to the input of the shaper of the controller of the same name those reflected signals, the first, second, third and outputs a reset output transmission permission flow control characters which are corresponding outputs of control unit, input "Prepared NULL» which is the same name input unit for generating a new state; the data flow control unit comprises a credit request generator, a received symbol counter, a transmitted symbol counter and a credit error detector, the first output of which is a credit error output of the data flow control unit, the data reception permission input and the ready control output symbol input are the first and second inputs, respectively credit request generator, the third input of which is connected to the status output of the counter of received symbols, the synchronization input of which is is the synchronization input of the data flow control unit and connected to the synchronization inputs of the credit request generator, the counter of transmitted symbols and the credit error detector, the reset input of the data flow control unit is connected to the reset inputs of the credit request generator, the counter of the received symbols, the transmitted symbol counter and the credit error detector, the first information input of which is connected to the output of a credit error of receiving a counter of received symbols, the first control input of which is connected n with the output of the credit request generator and is the output of the request for issuing the flow control symbol of the data flow control unit, the second control input of the received symbol counter is the input of acknowledging the information symbol of the data flow control unit, the input of which the acknowledgment of receiving the flow control symbol is the first control input of the transmitted counter characters, the second control input of which is an input for confirming the issuance of the information symbol of the poto control unit com of data, the second information input of the credit error detector is connected to the status output of the counter of transmitted symbols; the connection verification unit contains a communication support symbol decoder, a communication setup trigger, a standby counter, a first OR element, a second OR element, and an AND element, the output of which is the output of the connection error of the connection verification unit, the information input and the input of which special character is the first and second inputs, respectively the decoder of the communication support symbol, the output of the selection of the communication support symbol which is connected to the first input of the first OR element, the output of which is connected to the data input of the trigger communication ki, the connection establishment output of which is connected to the second input of the first OR element, to the first input of the AND element, and is the connection establishment block connection connection output, the input of the connection indicator of which is connected to the enable input of the decoder, with the inverse reset input of the communication setup trigger and with the first inverse the input of the second OR element, the output of the disconnect sign and the second input of which are connected respectively to the second input of the AND element and the transfer output of the standby counter, the decrement input of which connected to the synchronization input of the trigger to establish communication and is the synchronization input of the reception of the connection check unit, characterized in that it additionally contains the parameter register and decoder, the address input of which is an input of the type parameter of the system interface of the device, the input of which the parameter is connected to the control inputs the decoder and the parameter register, the information input of which is the input of the parameter value of the system interface of the device, the synchronization input of which is it is single with the synchronization input of the parameter register, the output of which is connected to the parameter inputs of the connection check unit, control unit and flow control unit, the recording input of which is connected to the first enable output of the decoder, the second and third enable outputs of which are connected to the write inputs of the control unit and the check unit, respectively connection, the reset input of which is connected to the second output of the reset of the control unit, and the control unit further comprises a connection counter, a register of delay constants and coincidence circuit, the first input of which is connected to the output of the delay constant register, the information input of which is the parameter input of the control unit, the recording input of which is the recording input of the delay constant register, the synchronization input of which is the synchronization input of the control unit, the reset input of which is connected to the inputs of the constant register delays and connection counter, the output of which is connected to the second input of the matching circuit, the output of which is connected to the second control input of the block Ia a new state, the control output driver control signals connected with the same input connections counter whose count input is an input local synchronization control unit. 2. The device according to claim 1, characterized in that the data flow control unit further comprises first and second constant registers and a comparator, the output of which is connected to the input of the error flag of the credit error detector, the second output of which is the output of the data output control unit of the data flow control unit, the status output of the counter of transmitted symbols is connected to the first input of the comparator, the second input of which is connected to the output of the register of the second constant, the information input of which is connected to the information input of the reg The first constant is the parameter input of the data flow control unit, the recording input of which includes a recording line of the first constant connected to the write input of the register of the first constant, and a recording line of the second constant connected to the write input of the register of the second constant, the synchronization input of which is connected to the input of the register of the first constant with the same name and is the synchronization input of the data flow control unit, the reset input of which is connected to the inputs of the same name of the register of the second constant and the register of the first th constant whose output is connected to the information input of the counter of received symbols. 3. The device according to claim 1, characterized in that the connection verification unit further comprises a disconnection parameter register and a third OR element, the output of which is connected to a load counter of the standby counter, the information input of which is connected to the output of the disconnection parameter register, the information input and recording input of which are respectively the input of the parameter and the write input of the connection check block, the synchronization input of which is the input of the load counter of the standby counter, the output of the decoder of the support symbol communication is connected to the first input of the third OR element, the second input of which is the reset input of the connection check unit.

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