JPS5884334A - Input and output controlling system - Google Patents

Abstract

PURPOSE:To simplify a program, by rewriting a channel program pointer by means of an execution starting instruction for the same channel program. CONSTITUTION:A storage device 2 stores an execution starting instruction for channel program and a channel program pointer which is designated by the execution starting instruction and contains the information of decision whether or not the address of the channel program as well as the program are converted into absolute addresses. A CPU1 decodes the execution starting instruction for channel program and indicates the start of execution of the program. An input/ output device 3 receives an indication for start of execution of the program and decodes the information of decision. In response to this action, the CPU1 decides to execute the program as it is by regarding that the program is converted into an absolute address or to execute the program by regarding the program as a logic address and converting it into an absolute address. In accordance with this decision, the channel program is executed.

Description

[Detailed description of the invention] The present invention relates to an input/output control method.

For example, when an information processing device inputs and outputs data from a device such as a magnetic disk, it creates a program as shown below and stores it at a specific address in the main storage device. In this case, the CPU creates a channel program written using logical addresses in the same way as a general program. This channel program is a program to be executed by the input/output control unit, but when executed, like a normal program, an appropriate absolute address ( This is a program that should be executed by converting a logical address to an absolute address.

However, conventional input/output control devices generally do not have a function to convert logical addresses to absolute addresses. Therefore, before starting the execution of the input/output command, the necessary buffer area is fixedly secured in the CPU Fi and main memory, and this channel program is converted into an absolute address, and then the execution start command of this channel program ( connect command). When this instruction is executed, the address syllable of the connect instruction (indicating the absolute address where this channel program storage has started)
is transferred to the CPU power control device, and the input/output control device sequentially reads out the channel program from the designated absolute address in the main memory, and thereafter executes input/output according to the commands independently of the CPU. Control.

Since this method does not require the input/output control device to convert logical addresses into absolute addresses, it is relatively simple, and most data processing devices have conventionally adopted this method.

However, according to this method, the buffer area necessary to execute this channel program is first secured in the main memory, the channel program is converted into an absolute address, and then input/output commands are started. However, in general input/output devices, it takes a long time from when an input/output command is started until the reserved buffer area is actually used. For example, when reading data from a magnetic disk, first move the magnetic disk to a specified position, wait until the specified position information is read, and then actually store it in the buffer area of the main storage device. The desired data is read. Therefore,
This method has the disadvantage that the area of the main storage device is not used for an unnecessarily long period of time and is fixed and secured in a wasteful manner.

In order to eliminate this drawback, channel duct (DAT:
Direct address restaurant DIRECTA A
A system called DDRB8S TRANSLATOR) is beginning to be used. This is because the CPU instructs the input/output control device to execute this channel program using the description tt in which the channel program is also placed at a logical address, and the input/output control device performs input/output processing while converting this logical address into an absolute address. There is a method of executing... An input/output control device for executing a channel program expressed in logical addresses is described in detail in, for example, Japanese Patent Laid-Open No. 56-40938.

Now, it has become necessary to provide two types of input/output control devices: one that does not perform absolute addressing, and one that performs absolute addressing. This has the disadvantage of complicating the program accordingly.

An object of the present invention is to provide an input/output control method that eliminates the above-mentioned conventional drawbacks.

The system of the present invention includes a channel program execution start command that instructs the start of execution of a channel program, and information specified by this command, the location address of the channel program, and determination information as to whether or not the program is an absolute address. a storage device for storing a channel program pointer including a channel program pointer; a central processing unit for decoding the channel program execution start command and instructing the program to start running; The receiver from the processing device decodes the determination information and in response, either assumes that the program is an absolute address and executes it as is, or assumes that it is an absolute address and executes it as is, or assumes that the program is an absolute address and uses an absolute address! and an input/output control device having means for determining whether to execute the channel program while converting it into a program, and accordingly executing the channel program.

Next, the present invention will be explained in detail with reference to fatty meat.

FIG. 1 is a block diagram showing one embodiment of the present invention.

This embodiment has a central processing unit [(hereinafter referred to as CPU) 1, a main storage device i2, and a human power control device 3, and the input/output control device [3 is configured to have a command line as shown in FIG. Register 30. It includes a command YfJ-f3, l, an execution control circuit 32, and a logical address/absolute address instruction flip 70 tab 33. , Now, the CPU 1 estimates the address of the instructions stored in the main memory device 2 via the control path 100, reads them out one after another via the data bus 200, and decodes them for depth. In this case, the instruction that instructs the execution of input/output is a logical connect instruction. As shown in FIG. 3), this field consists of an operation scene code field OP and an address syllable field A8. The field OP specifies that this is a specific input/output command, and the field As specifies the logical address (channel program storage address) where a channel program for specifically executing the input/output command is stored. It points to the logical address storing the channel program pointer pointing to the starting logical address).

Now, when the CPU decodes this logical connect command, it converts the contents of the address syllable A8 into a real address, and transfers this along with necessary information to the input/output control device 3 via the pig bus 200.

In the input/output control device 3, this information Fi is supplied to the execution control circuit 32 via the command register 30 and command decoder 31. The multi-channel circuit 32 recognizes that this is a command that indicates the absolute storage address of the channel program pointer and also indicates the start of execution of the channel program. Therefore, the circuit 32 supplies the designated absolute storage address of the i channel program pointer to the storage device 2 via the control bus 100, and transfers the channel program pointer to the pig bus 200.
and stores it in the command register 30.

This channel program pointer, as shown in FIG. It has an am address/absolute address identification field D for identifying whether it is written.

When this pointer is read into the command register 3o, the contents of the identification field D are decoded by the command decoder 31, and its output 310 and the output from the circuit 32 are
A signal 320 indicating that the channel program pointer is currently being decoded is supplied to the logical address/absolute address indicating flip 70 tab 33, and if the content of the identification field D specifies a logical address, is set. This set output 330 is provided to the execution control circuit 32, so that the circuit 32 identifies which channel program to be executed is located at the logical address including field P4 of the channel program pointer. Therefore, the content of the field P is converted from a logical address to an absolute address, the absolute address obtained in this way is supplied to the main memory device 2 via the control bus 100, and the first command of the specified channel program 2 is transferred to the data bus. 200 to the command register 30. It is supplied to the circuit 32 via the information line decoder 31 of the register 30, and the output of the flip-flop 33 (the flip-flop 33 retains the value set when the channel program pointer is decoded is 11). (and does not change even if other commands are decoded), if this is set, the address part included in each command is regarded as a logical address, and it is converted to an absolute address and sequentially executed. Execute channel program commands.

Furthermore, when field D of the channel program pointer is decoded, if the contents of field D do not specify a logical address (in other words, specify an absolute address), the decoder 31 Output 3 of
10 and the output 320 of the circuit 32 and the shift flip 7p.
The knob 33 is reset and reset. As a result, the circuit 32 identifies that the channel program to be executed from now on, including the contents of the channel program pointer, is written in absolute addresses, and the circuit 32 identifies the channel program pointer and the addresses of each command in the channel program pointer. It is assumed that all the specified parts are written in absolute addresses and is executed as is without performing the above-mentioned conversion from logical addresses to absolute addresses.

In the above explanation, a special logical address/absolute address identification field D is provided in the channel program pointer to indicate whether the channel program p-gram is written as a logical address or as an absolute address. If you specify, without creating a special field like this,
It may be determined that when a specific field in the pointer indicates a predetermined specific address, it indicates that it is described as a logical address. In this case, when the command decoder 31 decodes this specific address, it will generate the output 310. When 4° is decoded, the CP
U places the necessary address information for reading the channel program pointer in the input/output control device, and the input/output control device reads the channel program pointer using this sent address information and stores the information contained in this channel program pointer. In this case, we decided whether to decode the job type information and spread the decoding results to make it into an absolute address. Instead, you can also do the following when decoding an instruction (logical connect instruction), and then converting the address to The channel program pointer is read from the address specified by the syllable, and information instructing the start of the channel program and the contents of the channel program pointer are supplied to the input/output control device. The input/output control device identifies that the 19th channel program should be started based on the information supplied from the CPU, and by decoding the content of the supplied 9th channel program pointer, it determines the sushi start address of the p channel program and this address. It is determined whether or not the channel program should be converted into absolute addresses, and the channel program is executed accordingly. Similar effects can be expected using any of the above configurations.

As described above, when the present invention is used, the input/output control device converts absolute addresses as necessary by rewriting the channel program pointer using the same channel program execution start command (logical connect command). It is also possible to execute channel programs while
You can also make it run. This makes it possible to provide a highly flexible input/output control method.

[Brief explanation of drawings]

Figure 1 is a block diagram for explaining an embodiment of the present invention, Figure 2 is a 1912 diagram showing some details of this embodiment, and Figure 3 (2) Hiro channel 10-gram execution-former of the initial instruction. FIG. 3 is a diagram for explaining the format of the channel program pointer. In the figure, 1... Every center [9 positions (CPU), 2...
・Main storage device, 3... Input/output control device, 30'
...Command register, 31...Command decoder, 32...Execution control circuit, 33.
・・・・・・Ron m address/absolute honorary instruction pretend, puf p, p. 1st concave

Claims (1)

[Claims] A channel program execution start command for instructing the start of execution of a channel program, a location and address of the channel program specified by this command, and information on whether or not the program is an absolute address. a storage device that stores a channel program pointer including determination information; a central processing unit that decodes the channel program execution start command and instructs to start executing the program; and a central processing unit that receives the program execution start instruction from the central processing unit. deciphers the determination information and in response determines whether to consider the program to be an absolute address and execute it as is, or to consider it to be an address and execute it while converting it to an absolute address. an input/output control device having means for executing the channel program according to the method.