JP4721741B2 - Data processing module and message receiving method thereof - Google Patents

Description

  The present invention relates to a data processing module and a message receiving method thereof.

  In recent years, multi-master communication protocols have attracted attention as communication protocols. According to the multi-master communication protocol, when the bus is released, any of a plurality of communication nodes connected to the bus can transmit data on the bus, and the flexibility of the system is high. There are features. Such a multi-master communication protocol is used as a serial communication protocol between ECUs (electronic control units) in an automobile, and can be easily increased or decreased in communication nodes. In addition to the automobile field, it is also promising as a communication protocol in fields such as FA (Factory Automation), ships, and medical equipment.

  As an example of a multi-master communication protocol, a multi-master CAN (Controller Area Network, hereinafter referred to as CAN) protocol (standardized by ISO 11898 and ISO 11519 series) is known (see Patent Document 1). In the CAN protocol, the upper right column on page 34 of Patent Document 1 5) -3 Data Exchange DPRAM As shown below, a reception search process is performed to obtain the priority of a message prior to storing the received message. Further, prior to message transmission, a transmission search process for determining a message as a transmission candidate is performed. And the lower left column of page 35, 5) -3.6 As shown in the search process and FIG. 20, the search of the message buffer is performed as an operation that cannot be divided.

JP-A 61-195453

  A conventional CAN will be described with reference to the drawings. FIG. 5 is a block diagram schematically showing the configuration of the CAN device. FIG. 6 is a block diagram schematically showing the configuration of the message buffer of the CAN device.

  The CAN device 1 is a device in which a CAN module 2 (data processing module), a CPU 3, a RAM 4, and a peripheral circuit 5 are configured as one chip, and is electrically connected to a CAN transceiver (not shown) via a bus 6. Connected (see FIG. 5).

  The CAN module 2 is a data processing module that processes data, and includes a message handling unit 11, a message buffer 12, a CAN protocol transmission layer 13, and a mask set 14 (see FIG. 5).

  The message handling unit 11 performs processing for storing the received message in the message buffer 12, processing for selecting a message that is a transmission candidate from the messages stored in the message buffer 12, and the like (see FIG. 5). The message handling unit 11 performs transmission selection address generation unit (not shown) and transmission search comparison unit (not shown) in a part for selecting a message to be a transmission candidate from messages stored in the message buffer 12. And). In addition, the message handling unit 11 includes an ID comparison unit 23, a determination unit 24, a reception candidate address holding unit 25, and an initialization control unit 26 in a part that performs a store process in the message buffer 12 (FIG. 7). reference). In addition, the detailed structure of each structure part 23-26 is mentioned later.

  The message buffer 12 is a buffer that can store a predetermined number of messages (see FIG. 5), and is divided into a predetermined number of buffers (corresponding to a mailbox), and an address and a detailed address are assigned to each buffer. (See FIG. 6). Here, the detailed address includes the basic part (MIDL) of the identifier of the comparison target buffer, the value of control information such as the value of the control field (MCTRL), the extended part (MIDH), and the like. The message is information arranged in the order of an identifier (ID), a control field (control segment), and a message body (see FIG. 6). In addition to the message, status information such as transmission / reception setting information (MT), storage information (DN), and overwrite information (OWS) is stored in each buffer (see FIG. 6). Transmission / reception setting information (MT) is information including transmission setting or reception setting, and information including mask setting information in the case of reception setting. Note that the mask setting information is information indicating the setting conditions of a mask set (14 in FIG. 5) that masks a part of the ID, and whether or not a mask is used. For example, any one of mask 1 to mask 4) is included. Further, an identifier (ID) related to the reception setting is stored in the buffer whose transmission / reception setting information (MT) is the reception setting. The storage information (DN) is information indicating whether or not a message is stored. When “1”, the message is stored, and when “0”, the message is not stored. The overwriting information (OWS) is information indicating whether or not the message can be overwritten. When it is “1”, it can be overwritten, and when it is “0”, it cannot be overwritten.

  The CAN protocol transmission layer 13 transmits / receives data to / from a CAN transceiver (not shown) according to the CAN protocol (see FIG. 5).

  The mask set 14 is used when a predetermined part (for example, a part of ID) of a message is masked (see FIG. 5). For example, assuming that the ID is data consisting of four numbers, when 0533h is assigned to the address #n of the message buffer 12 having the buffers of the addresses # 0 to 31 as the ID related to the reception setting, the transmission / reception setting information ( When (MT) is “with mask 1”, 16 types of messages with ID = 053xh (x is 0 to 9, a to f) are stored in the buffer of address #n, and the transmission / reception setting information (MT) is “mask 2”. If “Yes”, 256 types of messages with ID = 05xxh (x is 0 to 9, a to f) are stored in the buffer at address #n, and if the transmission / reception setting information (MT) is “with mask 3”, ID = 4096h (x is 0 to 9, a to f) are stored in the buffer at address #n, and the transmission / reception setting information (MT) is “with mask 4” ID = xxxxh if (x is 0 to 9, a to f) so that the 65536 message types is stored in the buffer address #n.

  For example, the CPU 3 takes out data from various sensors (not shown) via the peripheral circuit 5, executes a desired process using the RAM 4, writes data to the message buffer 12, and stores the data in the message buffer 12. After taking out the written message and executing a desired process, a process of transmitting data to a display device (not shown) connected to the outside via the peripheral circuit 5 is performed (see FIG. 5).

  The peripheral circuit 5 is connected to, for example, various sensors (not shown) and a display device (not shown) provided outside the CAN device 1 and performs an interface between the outside and the inside of the CAN device 1 ( (See FIG. 5).

  Next, a CAN protocol transmission layer and a message handling unit of a conventional CAN device will be described with reference to the drawings. FIG. 7 is a block diagram schematically showing the configuration of the message handling unit and the CAN protocol transmission layer of the CAN device.

  The CAN protocol transmission layer 13 includes a storage processing unit 21 and a search address generation unit 22.

  The storage processing unit 21 is a part that performs processing for storing the received message in a buffer at a predetermined address of the message buffer 12. The storage processing unit 21 receives the message and outputs the received signal to the search address generation unit 22. Here, the received signal is a signal for indicating that a message has been received. Upon receiving the message, the storage processing unit 21 reads an ID (message ID) in the message and outputs the message ID to the ID comparison unit 23. When the reception search result valid flag from the determination unit 24 is level “1”, the storage processing unit 21 stores the message buffer 12 corresponding to the reception candidate address (held reception candidate address) from the reception candidate address holding unit 25. A message (received message) is output to the buffer at the address. Here, the reception search result valid flag is a flag indicating that the result of the reception search is valid, and is a flag for permitting the storage processing unit 21 to store the message. The message output from the storage processing unit 21 is stored in the buffer at the corresponding address. When the storage of the message is completed, the storage processing unit 21 sets (1) the storage information (DN) of the buffer at the corresponding address to “1”, and (2) transmits the storage completion information to the initialization control unit 26. After that, a new message is received.

  The search address generation unit 22 is a part that generates an address and a detailed address for searching for an address and a detailed address of the message buffer 12 by receiving a reception signal from the storage processing unit 21. For example, when there are addresses # 31 to # 0 in the message buffer 12 and there are detailed addresses (MIDH, MCTRL, MIDL) for each address, an address # 31 and its detailed address are generated, and then the address # 30 to ## Similar generation is performed in order up to zero. The search address generation unit 22 outputs the generated address and the detailed address (generated address, etc.) to the message buffer 12, and also outputs the generated address (only the generated address) to the reception candidate address holding unit 25. Output. When the generated address output from the search address generator 22 is input to the message buffer 12, (1) the reception setting ID is read from the buffer associated with the corresponding address, and the reception setting ID is compared with the ID. (2) The transmission / reception setting information (MT), storage information (DN) and overwriting information (OWS) of the buffer associated with the corresponding address are read out, and the transmission / reception setting information ( MT), the stored information (DN), and the overwriting information (OWS) are output toward the determination unit 24.

  The message handling unit 11 includes an ID comparison unit 23, a determination unit 24, a reception candidate address holding unit 25, and an initialization control unit 26 in a part that performs a store process in the message buffer 12.

  The ID comparison unit 23 is a part that compares whether the reception setting ID from the message buffer 12 matches the message ID from the storage processing unit 21. In the ID comparison unit 23, the reception setting IDs input sequentially and the message IDs are compared. The ID comparison unit 23 outputs a FIT signal (match signal; level “1”) to the determination unit 24 when the reception setting ID matches the message ID. When the reception setting ID and the message ID do not match, the FIT signal is not output (FIT signal is level “0”).

  The determination unit 24 should store a message based on the transmission / reception setting information (MT), storage information (DN), and overwrite information (OWS) from the message buffer 12 and the FIT signal from the ID comparison unit 23. This is the part that determines the superiority of the address. When the determination unit 24 determines that the address corresponding to the FIT signal is superior when the FIT signal (level “1”) is input from the ID comparison unit 23, the determination unit 24 proceeds toward the reception candidate address holding unit 25. A reception candidate address update signal (level “1”) is output, and a reception search result valid flag (level “1”) is output to the storage processing unit 21. Here, the reception candidate address update signal is a signal for updating the corresponding generated address input to the reception candidate address holding unit 25 as an address to be a reception candidate. The reception search result valid flag is a flag indicating that the result of the reception search is valid, and is a flag for allowing the storage processing unit 21 to store the message. The determination unit 24 initializes predetermined information held (inside the determination unit 24) by receiving an initialization signal from the initialization control unit 26. Here, the initialization signal is a signal for initializing predetermined information held in the determination unit 24. The detailed configuration of the determination unit 24 will be described later.

  When the reception candidate address holding unit 25 receives the reception candidate address update signal (level “1”) from the determination unit 24, the corresponding generation address from the search address generation unit 22 is updated as the reception candidate address. The part to hold. The reception candidate address holding unit 25 outputs the held reception candidate address toward the storage processing unit 21.

  The initialization control unit 26 receives the storage completion information from the storage processing unit 21 and outputs an initialization signal to the determination unit 24.

  Next, the determination unit of the message handling unit of the conventional CAN device will be described with reference to the drawings. FIG. 8 is a block diagram schematically showing the configuration of the determination unit of the CAN module according to the conventional example.

  The determination unit 24 includes a reception candidate MT storage unit 131, a reception candidate DN storage unit 132, a reception candidate OWS storage unit 133, an MT determination unit 134, a DN / OWS determination unit 135, and a superiority determination unit 136. A reception candidate address update determination unit 137 and a reception search result determination unit 138 are provided.

  The reception candidate MT holding unit 131 is a part that holds mask setting information of transmission / reception setting information (reception candidate MT) of an address that is a reception candidate. When the reception candidate MT holding unit 131 receives a reception candidate address update signal (level “1”) from the reception candidate address update determination unit 137, the reception candidate MT holding unit 131 outputs the reception candidate address update signal from the message buffer (12 in FIG. 7). The transmission / reception setting information (MT) is updated to mask setting information. The reception candidate MT holding unit 131 is initialized when receiving the initialization signal from the initialization control unit (26 in FIG. 7), and sets the mask setting information of the reception candidate MT in the state with the lowest priority (for example, There is a mask 4; see Table 1). The reception candidate MT holding unit 131 outputs the held mask setting information of the reception candidate MT to the MT determination unit 134. The priority of the mask setting information is, for example, “No mask” has the highest priority, and hereinafter, “With mask 1 (the last one digit mask of ID)”, “With mask 2 (the last two digits of ID) “Mask)”, “With mask 3 (the last three digits of the ID)”, and “With mask 4 (the last four digits of the ID)”, the order of priority decreases (see Table 1).

  The reception candidate DN holding unit 132 is a part that holds storage information (reception candidate DN) of addresses that are reception candidates. When receiving candidate address update signal (level “1”) is received from receiving candidate address update determining section 137, receiving candidate DN holding section 132 is output from the message buffer (12 in FIG. 7) at that time. Updated to storage information (DN). The reception candidate DN holding unit 132 outputs the held reception candidate DN toward the DN / OWS determination unit 135.

  The reception candidate OWS holding unit 133 is a part that holds the overwrite information (reception candidate OWS) of an address that is a reception candidate. When receiving candidate address update signal (level “1”) is received from receiving candidate address update determining section 137, receiving candidate OWS holding section 133 is output from the message buffer (12 in FIG. 7) at that time. Updated to overwrite information (OWS). The reception candidate OWS holding unit 133 outputs the held reception candidate OWS to the superiority determination unit 136.

  The combination of DN and OWS has the highest priority regardless of OWS when DN = 0, the second highest when DN = 1 and OWS = 1, and DN = 1. When OWS = 0, the lowest priority is given (see Table 2).

  The MT determination unit 134 compares the transmission / reception setting information (MT) from the message buffer (12 in FIG. 7) with the reception candidate MT from the reception candidate MT holding unit 131, and the superiority of the transmission / reception setting information (MT). This is a part for determining sex (MT determination). In the comparison between the MT and the reception candidate MT, the mask setting information is compared. The MT determination unit 134 determines “excellent” when the MT priority is high by comparing the MT and the reception candidate MT, determines “inferior” when the MT priority is low, and determines the MT and the reception candidate MT. Are determined to be “same” (see Table 1). The MT determination unit 134 outputs the MT determination information that is the determination result to the superiority determination unit 136.

  The DN / OWS determination unit 135 performs DN based on the storage information (DN) and overwrite information (OWS) from the message buffer (12 in FIG. 7) and the reception candidate DN from the reception candidate DN holding unit 132. And a combination of the OWS and the combination of the reception candidate DN and the reception candidate OWS to determine the superiority of the combination of the DN and the OWS (DN / OWS determination). Table 3 shows the criteria for determining the superiority of the combination of DN and OWS. The DN / OWS determination unit 135 outputs the DN / OWS determination information as the determination result, the DN, the OWS, and the reception candidate DN to the superiority determination unit 136. In FIG. 8, the DN / OWS determination unit 135 is configured not to receive the reception candidate OWS from the reception candidate OWS holding unit 133, but this is received in the DN / OWS determination of the DN / OWS determination unit 135. This is because the candidate OWS has no effect.

  The superiority determination unit 136 receives the MT determination information from the MT determination unit 134, the DN / OWS determination information from the DN / OWS determination unit 135, the DN, OWS, and the reception candidate DN, and the reception candidate OWS holding unit 133. This is a part for determining the superiority of the address of the buffer to store the message based on the candidate OWS. The superiority determination unit 136 includes a first write determination unit 136a, a second write determination unit 136b, and an overall determination unit 136c.

  The first write determination unit 136a is a part that determines whether the combination of DN and OWS is writable based on DN and OWS (first write determination). The first write determining unit 136a determines (1) “write is possible” regardless of OWS when DN = 0, and (2) “write is possible” when DN = 1 and OWS = 1. (3) When DN = 1 and OWS = 0, it is determined that “write is impossible” (see Table 4).

  The second writing determination unit 136b is a part that determines whether or not the combination of the reception candidate DN and the reception candidate OWS can be written based on the reception candidate DN and the reception candidate OWS (second writing determination). The second write determination unit 136b determines (1) “Writable” regardless of the reception candidate OWS when the reception candidate DN = 0, and (2) When the reception candidate DN = 1 and the reception candidate OWS = 1. When the reception candidate DN = 1 and the reception candidate OWS = 0, it is determined that “writing is impossible” (see Table 4).

  The overall determination unit 136c includes the MT determination information from the MT determination unit 134, the DN / OWS determination information from the DN / OWS determination unit 135, the first write determination result of the first write determination unit 136a, and the second Based on the second write determination result of the write determination unit 136b, the superiority of the address of the buffer in which the message is to be stored is comprehensively determined. The overall determination unit 136c (1) When the MT determination information is “excellent” and the DN / OWS determination information is “1”, the comprehensive determination unit 136c is superior regardless of the first write determination result and the second write determination result. When a determination signal (level “1”) is output and (2) the MT determination information is “excellent”, the DN / OWS determination information is “0”, and the first write determination result is “writable”, Regardless of the second write determination result, the superiority determination signal (level “1”) is output, and (3) the first write determination is performed when the MT determination information is “excellent” and the DN / OWS determination information is “0”. When the result is “not writable”, the superiority determination signal is not output regardless of the second write determination result (level “0”), and (4) the MT determination information is “same” and DN / When the OWS determination information is “1”, the superiority determination signal is transmitted regardless of the first write determination result and the second write determination result. (Level “1”) is output, and (5) when the MT determination information is “same” and the DN / OWS determination information is “0”, the first write determination result and the second write determination result are related. Therefore, the superiority determination signal is not output (level “0”), (6) the MT determination information is “poor”, the DN / OWS determination information is “1”, and the second write determination result is “writable”. , The superiority determination signal is not output regardless of the first write determination result (level “0”), (7) the MT determination information is “poor”, and the DN / OWS determination information is “1”. When the second write determination result is “unwritable”, the superiority determination signal (level “1”) is output regardless of the first write determination result, and (8) the MT determination information is “ If the DN / OWS determination information is “0”, the advantage is superior regardless of the first writing determination result and the second writing determination result. Determination signal is not outputted (level "0") (see Table 5).

  The reception candidate address update determination unit 137 is an AND circuit that determines whether or not the reception candidate address holding unit 25 updates the reception candidate address. The reception candidate address update determination unit 137 receives the superiority determination signal (level “1”) from the superiority determination unit 136 and the corresponding FIT signal (level “1”) from the ID comparison unit (23 in FIG. 7). , Is input to the reception candidate MT holding unit 131, the reception candidate DN holding unit 132, the reception candidate OWS holding unit 133, the reception search result determination unit 138, and the reception candidate address holding unit 25. An address update signal (level “1”) is output.

  The reception search result determination unit 138 is a flip-flop circuit unit that determines whether the reception search result is valid. The reception search result determination unit 138 receives the reception candidate address update signal (level “1”) from the reception candidate address update determination unit 137 and then receives an initialization signal (level “26” in FIG. 7). 1 "), level" 1 "is output as a reception search result valid flag. The reception search result determination unit 138 outputs the level “0” as the reception search result valid flag from when the initialization signal (level “1”) is received until the reception candidate address update signal is received.

  Next, the operation of the conventional CAN device (the operation when storing the received message) will be described.

  First, when a message is received by the storage processing unit (21 in FIG. 7), the message ID is output to the ID comparison unit (23 in FIG. 7), and the received signal is sent to the search address generation unit (in FIG. 7). 22). Next, an address and a detailed address (MIDH, MCTRL, MIDL) are generated by receiving the received signal at the search address generator (22 in FIG. 7).

  Next, the reception setting ID of the corresponding address is read from the message buffer (12 in FIG. 7) based on the generated address, and the message ID and the reception setting ID are read by the ID comparison unit (23 in FIG. 7). Are compared. When the message ID matches the reception setting ID, the FIT signal is output from the ID comparison unit (23 in FIG. 7). On the other hand, based on the generated address, transmission / reception setting information (MT), storage information (DN), and overwrite information (OWS) of the corresponding address are read from the message buffer (12 in FIG. 7). The determination unit (24 in FIG. 7) determines the superiority of each address based on the transmission / reception setting information (MT), the storage information (DN), the overwriting information (OWS), and the FIT signal. In determining the superiority of each address, the MT determination unit (134 in FIG. 8) determines the MT superiority based on the MT and the reception candidate MT, and the DN determination information (135 in FIG. 8). ), DN / OWS determination information that determines the superiority of the combination of DN and OWS based on DN, OWS, and reception candidate DN, and DN, OWS, and reception candidate from DN / OWS determination unit (135 in FIG. 8) Based on the DN and the reception candidate OWS, the superiority determination unit (136 in FIG. 8) performs a comprehensive determination of the superiority of the address of the buffer in which the message is to be stored. If it is determined that the superiority is high, the superiority determination signal is output from the superiority determination unit (136 in FIG. 8). When the superiority determination signal and the FIT signal are input to the reception candidate address update determination unit (137 in FIG. 8), the reception candidate address update signal is output, and the reception candidate result update unit (138 in FIG. 8) receives the reception candidate. When the address update signal is input, the reception search result valid flag is output.

  Next, when the reception candidate address holding signal (25 in FIG. 8) receives the reception candidate address update signal, it is updated to the latest generation address (reception candidate address) at that time, and the reception candidate address is stored in the storage processing unit ( It is output toward 21) in FIG. When the reception candidate address update signal is received by the reception candidate MT holding unit (131 in FIG. 8), the reception candidate DN holding unit (132 in FIG. 8), and the reception candidate OWS holding unit (133 in FIG. 8), Updated to MT, DN, OWS. Next, when the storage processing unit (21 in FIG. 7) receives the reception candidate address and the reception search result valid flag, the message is stored in the buffer of the address corresponding to the reception candidate address. When the message storage is completed, the storage processing unit (21 in FIG. 7) sets the storage information (DN) of the buffer at the corresponding address to “1” and goes to the initialization control unit (26 in FIG. 7). To output storage completion information. Upon receiving the storage completion information, the initialization control unit (26 in FIG. 7) outputs an initialization signal. When the reception candidate MT holding unit (131 in FIG. 8), the reception candidate DN holding unit (132 in FIG. 8), and the reception candidate OWS holding unit (133 in FIG. 8) receive initialization signals, they are initialized, The state with the lowest priority (reception candidate MT is “with mask 4”, reception candidate DN is “1”, reception candidate OWS is “0”). Thereafter, a new message is received by the storage processing unit (21 in FIG. 7).

  Next, the operation of the conventional CAN device (the operation when storing the received message) will be described using a specific example. FIG. 9 is a schematic diagram for explaining an operation in storing a message received in the CAN module according to the conventional example. FIG. 10 is a timing chart for explaining the operation in the storing process of the first message received in the CAN module according to the conventional example. FIG. 11 is a timing chart for explaining the operation in storing the second message received in the CAN module according to the conventional example.

  Here, in the message buffer, four addresses in which a reception setting ID, transmission / reception setting information (MT), storage information (DN), and overwrite information (OWS) as shown in FIG. 9A are set as initial setting conditions. There shall be. Further, the ID (= 0533h) of the first message is the same as the ID (= 0533h) of the second message. For convenience of explanation, a case where the address of the message buffer is # 4 to # 1 will be described.

  A case where the first message (ID = 0533h) is received will be described. When the first message is received, a search is performed from message buffer address # 4 to # 1. For address # 4, since the reception setting ID is 0333h and the ID of the first message is 0533h, the FIT signal is not output because there is no match, the reception candidate address update signal is not output, and the reception search result valid flag Is “0”, the first message is not stored in the buffer at address # 4 (see FIGS. 9A and 10). Next, since address # 3 is a transmission setting (no reception setting ID), the first message is not stored in the buffer of address # 3 (see FIGS. 9A and 10). .

  Next, for address # 2, since the reception setting ID is 0533h and the ID of the first message is 0533h, the FIT signal is output, the MT is “no mask”, and the reception candidate MT is “with mask 4”. Therefore, the MT determination information is “excellent” (see Table 1), DN / OWS is “0”, OWS is “0”, reception candidate DN is “1”, and reception candidate OWS is “0”. Since the determination information is “1” (see Table 3), the superiority determination signal (level “1”) is output (see Table 5), the reception candidate address update signal is output, and the reception candidate MT is “no mask”. ”, The reception candidate DN is“ 0 ”, the reception candidate OWS is“ 0 ”, the reception candidate address is updated to“ address # 2 ”, and the reception search result valid flag is“ 1 ”. # 2 buffer It will be accommodated (FIG. 9 (A), the see Figure 10).

  Next, for address # 1, since MT is “with mask 2” and reception candidate MT is “without mask”, the MT determination information is “poor” (see Table 1), DN is “0”, and OWS is Since “1” is the reception candidate DN “0” and the reception candidate OWS is “0”, the DN / OWS determination information is “1” (see Table 3), and the reception candidate DN is “0” and the reception candidate OWS. Since the second write determination result is “writable” because “0” is “0” (see Table 4), the superiority determination signal is not output (see Table 5), and the reception candidate address update signal is output. Since the reception candidate address remains “address # 2”, the first message is not stored in the buffer of address # 1 (see FIG. 9A and FIG. 10).

  When the first message is stored, the storage information (DN) at address # 2 is rewritten from 0 to 1 (see FIG. 9B).

  A case where the second message (ID = 0533h) is received will be described. For address # 4, since the reception setting ID is 0333h and the ID of the second message is 0533h, the FIT signal is not output, the reception candidate address update signal is not output, and the reception search result valid flag is “0”. Therefore, the second message is not stored in the buffer at address # 4 (see FIG. 9B and FIG. 11). Next, since address # 3 is a transmission setting (no reception setting ID), the second message is not stored in the buffer of address # 3 (see FIGS. 9B and 11). .

  Next, for address # 2, since the reception setting ID is 0533h and the ID of the second message is 0533h, the FIT signal is output because they match, but the MT is “no mask” and the reception candidate MT is “mask” MT determination information is “excellent” because “4 is present” (see Table 1), DN is “1”, OWS is “0”, reception candidate DN is “1”, and reception candidate OWS is “0”. Therefore, the DN / OWS determination information is “0” (see Table 3), and since the DN is “1” and the OWS is “0”, the first write determination result is “not writable” (Table 4). Since the superiority determination signal is not output (level “0”; see Table 5), the reception candidate address update signal is not output, and the reception search result valid flag is “0”, the second message is address # 2 is not stored in the buffer (FIG. 9B) See Figure 11).

  Next, for address # 1, since the reception setting ID is 0533h and the ID of the second message is 0533h, the FIT signal is output because they match, the MT is “with mask 2”, and the reception candidate MT is “no mask” Therefore, the MT determination information is “poor” (see Table 1), DN is “0”, OWS is “1”, reception candidate DN is “1”, and reception candidate OWS is “0”. Since the / OWS determination information is “1” (see Table 3) and the reception candidate DN is “1” and the reception candidate OWS is “0”, the second write determination result is “unwritable” ( Table 4), a superiority determination signal (level “1”) is output, a reception candidate address update signal is output, reception candidate MT is “with mask 2”, reception candidate DN is “0”, and reception candidate OWS is “1”, the reception candidate address is “address # 1 Updated on, because the receiving search results valid flag is "1", so that the second message is stored in the buffer of the address # 1 (FIG. 9 (B), the reference 11).

  When the second message is stored, the storage information (DN) of address # 1 is rewritten from 0 to 1 (see FIG. 9C).

  Here, the problem with the conventional CAN device is that when the high priority message buffer is full and overwriting is prohibited, the next message is written to the next priority buffer. Thus, in order for the CPU to read the data of the message with ID = 0533h from the message buffer, it must read from the buffer of the two addresses of address # 2 and address # 1, and must read a plurality of data. Since the CPU has to decide which process to use and which of the read data is to be used, extra processing is necessary.

In a first aspect of the present invention, in the data processing module connected to a network of multi-master mode, messages are divided into a predetermined number of buffers capable of storing and, in response to each pre-Symbol buffer, receiving setting information that indicates whether the transmission setting or reception setting, storing information indicating whether the storage of the message, and a message buffer overwriting information indicating whether the overwrite message is stored, associated with the received message By comparing the identifier and the identifier determined based on the transmission / reception setting information associated with the buffer, the buffer corresponding to the identifier associated with the received message is selected from the message buffer. According to the comparison result of the identifier comparison unit to be detected and the identifier comparison unit, Based on the transmission / reception setting information stored in the buffer, the storage information at the time of receiving the message, and the overwrite information, the buffer for storing the received message is specified, and the storage of the message is permitted. A determination unit that receives the first message associated with the first identifier, and the identifier comparison unit is associated with the first identifier. When the first buffer and the second buffer are detected, the transmission / reception setting information related to the first buffer and the second buffer is a reception setting, and the first identifier is set in the first buffer. A second message associated with the first buffer is stored, the storage information associated with the first buffer indicates that a message is stored, and the first If the overwrite information relating to Ffa detects that indicating the disable overwriting is characterized in that it does not allow storage of the first buffer and the second buffer of the first message.

In the second aspect of the present invention, a data processing module connected to a multi-master network is composed of a plurality of buffers, and each buffer has identification information for identifying data and whether or not the buffer can be overwritten. A message buffer including mask information for masking identification information of the buffer, identification information of all of the plurality of buffers in the message buffer and the mask when received data is received The identification information obtained from the information is compared with the identification information of the received data, and when the identification information of a plurality of buffers matches, the buffer having the highest priority is selected according to the mask information, and the selection When the overwrite information in the designated buffer indicates that writing is not possible, the selected buffer And characterized in that it comprises a control circuit for processing the received data without writing the data to another buffer.

According to a third aspect of the present invention, in the message reception method of the data processing module connected to the multi-master network, the first message is stored in the buffer associated with the first address of the message buffer. And the first address is received when a second message to which the same identifier as the identifier of the first message is given cannot be overwritten on the buffer related to the first address. The second message is not stored in a buffer associated with a second address having a lower priority than the second address.

According to the present invention (claim 1 7), it is not that more data will be stored in a distributed. Also, no extra processing occurs when the CPU reads a message from the message buffer. Further, the CPU processing is speeded up, and high performance as a system can be exhibited. Further, even when the reception history is traced, no extra processing occurs.

  A data processing module according to Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram schematically illustrating a configuration of a determination unit of a CAN module (data processing module) according to the first embodiment of the present invention.

  The determination unit 24 of the CAN module (data processing module) according to the first embodiment is used as a message handling unit (11 in FIG. 7) of the CAN module (2 in FIG. 5; data processing module) in the CAN device (1 in FIG. 5). Is provided. Components other than the determination unit 24 of the CAN module (data processing module) according to the first embodiment are the same as other components other than the determination unit of the conventional CAN module. For the overall configuration (configuration other than the determination unit) of the CAN module (data processing module), refer to FIGS. 5 to 7 and the description of the conventional example corresponding to these drawings.

  Referring to FIG. 7, the determination unit 24 is based on transmission / reception setting information (MT), storage information (DN) and overwriting information (OWS) from the message buffer 12, and the FIT signal from the ID comparison unit 23. This is a part for determining the superiority of the address where the message is stored. When the determination unit 24 determines that the address corresponding to the FIT signal is superior when the FIT signal (level “1”) is input from the ID comparison unit 23, the determination unit 24 proceeds toward the reception candidate address holding unit 25. A reception candidate address update signal (level “1”) is output, and a reception search result valid flag (level “1”) is output to the storage processing unit 21. Here, the reception candidate address update signal is a signal for updating the corresponding generated address input to the reception candidate address holding unit 25 as an address to be a reception candidate. The reception search result valid flag is a flag indicating that the result of the reception search is valid, and is a flag for allowing the storage processing unit 21 to store the message. The determination unit 24 initializes predetermined information held (inside the determination unit 24) by receiving an initialization signal from the initialization control unit 26. In addition, the determination part of the data processing module which concerns on Embodiment 1 differs in the determination method from the determination part of the data processing module which concerns on a prior art example.

  Referring to FIG. 1, the determination unit 24 includes a reception candidate MT holding unit 31, a reception candidate DN holding unit 32, a reception candidate OWS holding unit 33, an MT determination unit 34, and a DN / OWS determination unit 35. And a reception search result update determination unit 38, a reception search result update mask determination unit 39, and a reception search result determination unit 40.

  The reception candidate MT holding unit 31 is a part that holds mask setting information of transmission / reception setting information (reception candidate MT) of an address that is a reception candidate. When the reception candidate MT holding unit 31 receives the reception candidate address update signal (level “1”) from the reception candidate address update determination unit 37, the message is output from the message buffer (12 in FIG. 7) at that time. The transmission / reception setting information (MT) is updated to mask setting information. The reception candidate MT holding unit 31 is initialized when receiving the initialization signal from the initialization control unit (26 in FIG. 7), and sets the mask setting information of the reception candidate MT in the state with the lowest priority (for example, With mask 4; see Table 1). The reception candidate MT holding unit 31 outputs the held mask setting information of the reception candidate MT to the MT determination unit 34. Note that the reception candidate MT holding unit 31 of the first embodiment is the same as the reception candidate MT holding unit (131 in FIG. 8) of the conventional example.

  The reception candidate DN holding unit 32 is a part that holds storage information (reception candidate DN) of addresses that are reception candidates. When receiving candidate address update signal (level “1”) is received from receiving candidate address update determining unit 37, receiving candidate DN holding unit 32 is output from the message buffer (12 in FIG. 7) at that time. Updated to storage information (DN). The reception candidate DN holding unit 32 is initialized when receiving an initialization signal from the initialization control unit (26 in FIG. 7), and the reception candidate DN is selected when the combination of DN and OWS has the lowest priority. The DN state is set (level “1”; see Table 2). The reception candidate DN holding unit 32 outputs the held reception candidate DN toward the DN / OWS determination unit 35 and the reception search result valid mask determination unit 39. Note that the reception candidate DN holding unit 32 of the first embodiment outputs the reception candidate DN toward the reception search result valid mask determination unit 39, so that the conventional reception candidate DN holding unit (132 in FIG. 8). And different.

  The reception candidate OWS holding unit 33 is a part that holds the overwrite information (reception candidate OWS) of an address that is a reception candidate. When the reception candidate OWS holding unit 33 receives the reception candidate address update signal (level “1”) from the reception candidate address update determination unit 37, it is output from the message buffer (12 in FIG. 7) at that time. Updated to overwrite information (OWS). The reception candidate OWS holding unit 33 is initialized when receiving an initialization signal from the initialization control unit (26 in FIG. 7), and the reception candidate OWS is a combination of DN and OWS with the lowest priority. The OWS state is set (level “0”; see Table 2). The reception candidate OWS holding unit 33 outputs the held reception candidate OWS to the reception search result valid mask determination unit 39. The reception candidate OWS holding unit 33 according to the first embodiment outputs the reception candidate OWS toward the reception search result valid mask determination unit 39 and does not output the reception candidate OWS toward the superiority determination unit 36. This is different from the conventional reception candidate OWS holding unit (133 in FIG. 8).

  The MT determination unit 34 compares the transmission / reception setting information (MT) from the message buffer (12 in FIG. 7) with the reception candidate MT from the reception candidate MT holding unit 31 to determine the superiority of the transmission / reception setting information (MT). This is a part for determining sex (MT determination). In the comparison between the MT and the reception candidate MT, the mask setting information is compared. The MT determination unit 34 determines “excellent” when the MT priority is high by comparing the MT and the reception candidate MT, and determines “inferior” when the MT priority is low. Are determined to be “same” (see Table 1). The MT determination unit 34 outputs the MT determination information that is the determination result toward the superiority determination unit 36. The MT determination unit 34 of the first embodiment is the same as the MT determination unit (134 in FIG. 8) of the conventional example.

  The DN / OWS determination unit 35 performs DN processing based on the storage information (DN) and overwrite information (OWS) from the message buffer (12 in FIG. 7) and the reception candidate DN from the reception candidate DN holding unit 32. And a combination of the OWS and the combination of the reception candidate DN and the reception candidate OWS to determine the superiority of the combination of the DN and the OWS (DN / OWS determination). The criteria for determining the superiority of the combination of DN and OWS are as follows. (1) When DN is “0” (can be stored), it is determined as “1” regardless of OWS, reception candidate DN, and reception candidate OWS, and (2) DN is “1” (cannot be stored) and OWS is When “0” (overwriting is impossible), the reception candidate DN and the reception candidate OWS are determined to be “0”. (3) DN is “1” (cannot be stored) and OWS is “1” (overwriting) Possible) and the reception candidate DN is “0”, it is determined as “0” regardless of the reception candidate OWS. (4) DN is “1” (cannot be stored) and OWS is “1” (can be overwritten) When the reception candidate DN is “1”, the reception candidate OWS is determined to be “1” (see Table 3). The DN / OWS determination unit 35 outputs DN / OWS determination information, which is a determination result, toward the superiority determination unit 36. Here, in FIG. 1, the DN / OWS determination unit 35 is configured not to receive the reception candidate OWS from the reception candidate OWS holding unit 33, but this is the case in the DN / OWS determination of the DN / OWS determination unit 35. This is because the reception candidate OWS has no effect. However, the DN / OWS determination unit 35 may be configured to receive the reception candidate OWS from the reception candidate OWS holding unit 33. Note that the DN / OWS determination unit 35 of the first embodiment does not output the DN, OWS, and reception candidate DN to the superiority determination unit 36, so that the DN / OWS determination unit of the conventional example (135 in FIG. 8). ) Is different.

  Based on the MT determination information from the MT determination unit 34 and the DN / OWS determination information from the DN / OWS determination unit 35, the superiority determination unit 36 determines the superiority of the address of the buffer in which the message is to be stored. It is a part to do. The superiority determination unit 36 outputs (1) the superiority determination signal (level “1”) regardless of the DN / OWS determination information when the MT determination information is “excellent”, and (2) the MT determination When the information is “same” and the DN / OWS determination information is “1”, the superiority determination signal (level “1”) is output. (3) The MT determination information is “same” and the DN / OWS determination information. When “0” is “0”, the superiority determination signal is not output (level “0”). (4) When the MT determination information is “inferior”, the superiority is determined regardless of the DN / OWS determination information. The determination signal is not output (level “0”) (see Table 6). The superiority determination unit 36 of the first embodiment performs determination based only on the MT determination information and the DN / OWS determination information. If the MT determination information is “excellent”, the superiority determination signal is always “1”. , And when the MT determination information is “poor”, the superiority determination signal is always “0”, which is different from the conventional superiority determination unit (136 in FIG. 8, Table 5).

  The reception candidate address update determination unit 37 is an AND circuit that determines whether or not the reception candidate address holding unit 25 updates the reception candidate address. The reception candidate address update determination unit 37 receives the superiority determination signal (level “1”) from the superiority determination unit 36 and the corresponding FIT signal (level “1”) from the ID comparison unit (23 in FIG. 7). , Are received toward the reception candidate MT holding unit 31, the reception candidate DN holding unit 32, the reception candidate OWS holding unit 33, the reception search result update determination unit 38, and the reception candidate address holding unit 25. A candidate address update signal (level “1”) is output.

  The reception search result update determination unit 38 is an RS flip-flop circuit unit that determines whether or not to update the reception search result. The reception search result update determination unit 38 receives the reception candidate address update signal (level “1”) from the reception candidate address update determination unit 37 and then receives an initialization signal (level 26) from the initialization control unit (26 in FIG. 7). Until receiving “1”), the level “1” is output as the reception search result update flag. The reception search result update determination unit 38 outputs level “0” as the reception search result update flag from the time when the initialization signal (level “1”) is received until the reception candidate address update signal is received. Here, the reception search result update flag is a flag for determining whether or not to update the reception search result.

  The reception search result validity mask determination unit 39 is a logic circuit that determines whether or not to validate the reception search result. The reception search result valid mask determination unit 39 generates a reception search result valid mask signal based on the reception candidate DN from the reception candidate DN holding unit 32 and the reception candidate OWS from the reception candidate OWS holding unit 33. The reception search result valid mask determination unit 39 sets the reception search result valid mask signal to “0” when the reception candidate DN is “1” and the reception candidate OWS is “0”, and (2) the reception candidate DN is The reception search result valid mask signal is set to “1” when the reception candidate OWS is “1” at “1”, and (3) the reception search result when the reception candidate DN is “0” and the reception candidate OWS is “0”. The effective mask signal is set to “1”, and (4) the reception search result effective mask signal is set to “1” when the reception candidate DN is “0” and the reception candidate OWS is “1”. Here, the reception search result valid mask signal is a signal for masking the reception search result valid signal. The reception search result valid mask determination unit 39 is a component that was not found in the conventional example.

  The reception search result determination unit 40 is an AND circuit that determines whether the reception search result is valid. The reception search result determination unit 40 determines whether the reception search result is valid based on the reception search result update flag from the reception search result update determination unit 38 and the reception search result valid mask signal from the reception search result validity mask determination unit 39. Output a flag. The reception search result determination unit 40 outputs a reception search result valid flag (level “1”) when the reception search result update flag is “1” and the reception search result valid mask signal is “1”. The reception search result valid flag is not output (level “0”).

  Next, the operation of the CAN module (data processing module) according to the first embodiment (the operation when storing a received message) will be described.

  First, when a message is received by the storage processing unit (21 in FIG. 7), the message ID is output to the ID comparison unit (23 in FIG. 7), and the received signal is sent to the search address generation unit (in FIG. 7). 22). Next, an address and a detailed address (MIDH, MCTRL, MIDL) are generated by receiving the received signal at the search address generator (22 in FIG. 7).

  Next, the reception setting ID of the corresponding address is read from the message buffer (12 in FIG. 7) based on the generated address, and the message ID and the reception setting ID are read by the ID comparison unit (23 in FIG. 7). Are compared. When the message ID matches the reception setting ID, the FIT signal is output from the ID comparison unit (23 in FIG. 7). On the other hand, based on the generated address, transmission / reception setting information (MT), storage information (DN), and overwrite information (OWS) of the corresponding address are read from the message buffer (12 in FIG. 7). The determination unit (24 in FIG. 7) determines the superiority of each address based on the transmission / reception setting information (MT), the storage information (DN), the overwriting information (OWS), and the FIT signal. In determining the superiority of each address, the MT determination unit (34 in FIG. 1) determines MT superiority based on the MT and the reception candidate MT, and the DN / OWS determination unit (35 in FIG. 1). ) And the DN / OWS determination information that determines the superiority of the combination of DN and OWS based on DN, OWS, and reception candidate DN, and stores the message in the superiority determination unit (36 in FIG. 1). Comprehensive determination of the superiority of the buffer address to be performed. If it is determined that the superiority is high, an advantage determination signal is output from the superiority determination unit (36 in FIG. 1). When the superiority determination signal and the FIT signal are input to the reception candidate address update determination unit (37 in FIG. 1), a reception candidate address update signal is output. Next, when the reception candidate address holding signal (25 in FIG. 1) receives the reception candidate address update signal, it is updated to the latest generation address (reception candidate address) at that time, and the reception candidate address is stored in the storage processing unit ( It is output toward 21) in FIG. When the reception candidate address update signal is received by the reception candidate MT holding unit (31 in FIG. 1), the reception candidate DN holding unit (32 in FIG. 1), and the reception candidate OWS holding unit (33 in FIG. 1), respectively. Updated to MT, DN, OWS.

  Next, when a reception candidate address update signal is input to the reception search result update determination unit (38 in FIG. 1), a reception search result update signal (level “1”) is output. When a reception candidate DN (for example, level “0”) and a reception candidate OWS (for example, level “0”) are input to the reception search result effective mask determination unit (39 in FIG. 1), the reception search result effective mask signal (level “1”) is output. When a reception search result update signal (level “1”) and a reception search result valid mask signal (level “1”) are input to the reception search result determination unit (40 in FIG. 1), a reception search result valid flag is output. The

  Next, when the storage processing unit (21 in FIG. 7) receives the reception candidate address and the reception search result valid flag, the message is stored in the buffer of the address corresponding to the reception candidate address. When the message storage is completed, the storage processing unit (21 in FIG. 7) sets the storage information (DN) of the buffer at the corresponding address to “1” and goes to the initialization control unit (26 in FIG. 7). To output storage completion information. Upon receiving the storage completion information, the initialization control unit (26 in FIG. 7) outputs an initialization signal. When the reception candidate MT holding unit (31 in FIG. 1), the reception candidate DN holding unit (32 in FIG. 1), and the reception candidate OWS holding unit (33 in FIG. 1) receive the initialization signals, they are initialized, The state with the lowest priority (reception candidate MT is “with mask 4”, reception candidate DN is “1”, reception candidate OWS is “0”). Thereafter, a new message is received by the storage processing unit (21 in FIG. 7).

  Next, the operation of the CAN module (data processing module) according to the first embodiment (the operation when storing the received message) will be described using a specific example. FIG. 2 is a schematic diagram for explaining an operation in the received message storage process in the CAN module (data processing module) according to the first embodiment of the present invention. FIG. 3 is a timing chart for explaining the operation at the time of storing the first message received by the CAN module (data processing module) according to the first embodiment of the present invention. FIG. 4 is a timing chart for explaining the operation during the storing process of the second message received by the CAN module (data processing module) according to the first embodiment of the present invention.

  Here, in the message buffer, as initial setting conditions (similar to those used in the conventional example), the reception setting ID, transmission / reception setting information (MT), storage information (DN), and overwrite information as shown in FIG. Assume that there are four addresses for which (OWS) is set. Further, the ID (= 0533h) of the first message is the same as the ID (= 0533h) of the second message. For convenience of explanation, a case where the address of the message buffer is # 4 to # 1 will be described.

  A case where the first message (ID = 0533h) is received will be described. When the first message is received, a search is performed from message buffer address # 4 to # 1. For address # 4, since the reception setting ID is 0333h and the ID of the first message is 0533h, the FIT signal is not output because there is no match, the reception candidate address update signal is not output, and the reception search result update flag Is “0” and the reception search result valid flag is “0”, the first message is never stored in the buffer at address # 4 (see FIGS. 2A and 3). Next, since address # 3 is a transmission setting (no reception setting ID), the first message is not stored in the buffer of address # 3 (see FIGS. 2A and 3). .

  Next, for address # 2, since the reception setting ID is 0533h and the ID of the first message is 0533h, the FIT signal is output, the MT is “no mask”, and the reception candidate MT is “with mask 4”. Therefore, since the MT determination information is “excellent” (see Table 1), the superiority determination signal (level “1”) is output (see Table 6), the reception candidate address update signal is output, and the reception candidate MT is “No mask”, reception candidate DN is “0”, reception candidate OWS is “0”, reception candidate address is updated to “address # 2”, and a reception search result valid mask signal (level “1”) is output, Since the reception search result update flag becomes “1” and the reception search result valid flag becomes “1”, the first message is stored in the buffer at address # 2 (FIG. 2A, FIG. 3). reference)

  Next, for the address # 1, since the MT is “with mask 2” and the reception candidate MT is “without mask”, the MT determination information is “poor” (see Table 1), so the superiority determination signal is output. (See Table 6), the reception candidate address update signal is not output, and the reception candidate address remains “address # 2”, so that the first message is not stored in the buffer of address # 1 ( (Refer FIG. 2 (A) and FIG. 3).

  When the first message is stored, the storage information (DN) at address # 2 is rewritten from 0 to 1 (see FIG. 2B).

  A case where the second message (ID = 0533h) is received will be described. For address # 4, since the reception setting ID is 0333h and the ID of the second message is 0533h, the FIT signal is not output, the reception candidate address update signal is not output, and the reception search result update flag is “0”. ”, Since the reception search result valid flag is“ 0 ”, the second message is not stored in the buffer at address # 4 (see FIG. 2B and FIG. 4). Next, since address # 3 is a transmission setting (no reception setting ID), the second message is not stored in the buffer of address # 3 (see FIGS. 2B and 4). .

  Next, for address # 2, since the reception setting ID is 0533h and the ID of the second message is 0533h, the FIT signal is output because they match, the MT is “no mask”, and the reception candidate MT is “with mask 4” Since the MT determination information is “excellent” (see Table 1), the superiority determination signal is output (see Table 6), the reception candidate address update signal is output, and the reception candidate MT is “no mask”. The reception candidate DN is “1”, the reception candidate OWS is “0”, the reception candidate address is updated to “address # 2”, and the reception search result update flag is “1”, but the reception candidate DN is “1”. Since the reception candidate OWS is “0” and the reception search result valid flag is “0”, the second message is not stored in the buffer of the address # 2 (see FIG. 2B and FIG. 4).

  Next, for the address # 1, since the reception setting ID is 0533h and the ID of the second message is 0533h, the FIT signal is output because they match, but the MT is “with mask 2” and the reception candidate MT is “ Since it is “no mask”, the MT determination information is “poor” (see Table 1), the superiority determination signal is not output (level “0”), the reception candidate address update signal is not output, and the reception candidate address Remains at “address # 2”, the second message is not stored in the buffer at address # 1 (see FIG. 2B and FIG. 4).

  Since the second message is not stored, the storage information (DN) at any address is not rewritten (see FIG. 2C).

  In this state, in order for the CPU to read the message with ID = 0533h, it is only necessary to read from the buffer # 2. That is, the CPU only needs to perform read access to a specific single buffer of the message buffer.

  According to the first embodiment, since extra data is not distributed and stored, no extra processing occurs when the CPU reads a message from the message buffer. Therefore, the CPU processing is speeded up, and high performance as a system can be exhibited. Similarly, no extra processing occurs even when the reception history is traced.

It is the block diagram which showed typically the structure of the determination part of the CAN module (data processing module) which concerns on Embodiment 1 of this invention. It is a schematic diagram for demonstrating the operation | movement in the case of the storage process of a received message in the CAN module (data processing module) which concerns on Embodiment 1 of this invention. It is a timing chart for demonstrating the operation | movement in the case of the storage process of the 1st message received in the CAN module (data processing module) which concerns on Embodiment 1 of this invention. It is a timing chart for demonstrating the operation | movement in the case of the storage process of the 2nd message received in the CAN module (data processing module) which concerns on Embodiment 1 of this invention. It is the block diagram which showed the structure of the CAN device typically. It is the block diagram which showed typically the structure of the message buffer of a CAN device. It is the block diagram which showed typically the structure of a part (part which stores the received message in a message buffer) of the message handling part of a message buffer. It is the block diagram which showed typically the structure of the determination part of the CAN module which concerns on a prior art example. It is a schematic diagram for demonstrating the operation | movement in the case of the storage process of the message received in the CAN module which concerns on a prior art example. It is a timing chart for demonstrating the operation | movement at the time of the storage process of the 1st message received in the CAN module which concerns on a prior art example. It is a timing chart for demonstrating the operation | movement at the time of the storage process of the 2nd message received in the CAN module which concerns on a prior art example.

Explanation of symbols

1 CAN device 2 CAN module (data processing module)
3 CPU
4 RAM
DESCRIPTION OF SYMBOLS 5 Peripheral circuit 6 Bus 11 Message handling part 12 Message buffer 13 CAN protocol transmission layer 14 Mask set 21 Storage process part 22 Search address generation part 23 ID comparison part (identifier comparison part)
24 determination unit 25 reception candidate address holding unit 26 initialization control unit 31, 131 reception candidate MT holding unit (reception candidate transmission / reception setting information holding unit)
32, 132 Reception candidate DN holding unit (reception candidate storage information holding unit)
33, 133 Reception candidate OWS holding unit (reception candidate overwrite information holding unit)
34, 134 MT determination unit (transmission / reception setting information determination unit)
35, 135 DN / OWS determination unit (stored information / overwrite information determination unit)
36, 136 Superiority determination unit 37, 137 Reception candidate address update determination unit 38 Reception search result update determination unit 39 Reception search result valid mask determination unit 40, 138 Reception search result determination unit 136a First write determination unit 136b Second book Included judgment part 136c Comprehensive judgment part

Claims (7)

Messages are divided into a predetermined number of buffers capable of storing and pre SL corresponding to each buffer, transceiver setting information indicating whether transmission setting or reception setting, storing information indicating whether the storage of the message and, A message buffer in which overwrite information indicating whether or not the message can be overwritten is stored;
The buffer corresponding to the identifier associated with the received message by comparing an identifier associated with the received message with an identifier determined based on the transmission / reception setting information associated with the buffer An identifier comparison unit for detecting the message buffer from the message buffer;
Based on the comparison result of the identifier comparison unit, based on the transmission / reception setting information stored in each of the buffers, the storage information at the time of receiving the message, and the overwrite information, the received message A determination unit that identifies a buffer to be stored and permits storage of the message ;
With
The determination unit receives a first message associated with a first identifier, and the identifier comparison unit includes a first buffer and a second buffer associated with the first identifier. When the first and second buffers are detected, the transmission / reception setting information related to the first buffer and the second buffer is a reception setting, and the second buffer associated with the first identifier in the first buffer When a message is stored, the stored information related to the first buffer indicates that the message is stored, and it is detected that the overwrite information related to the first buffer indicates that overwriting is not possible In the data processing module , storage of the first message in the first buffer and the second buffer is not permitted . The said 2nd message stored in the said 1st buffer is read from CPU, when storing of the said 1st message is not permitted by the said determination part. Data processing module. The determination unit does not permit storage of the first message in the first buffer and the second buffer when the transmission / reception setting information stored in each of the buffers is a transmission setting. The data processing module according to claim 1 or 2. A message composed of a plurality of buffers, each of which includes identification information for identifying data, overwrite information indicating whether the buffer can be overwritten, and mask information for masking the buffer identification information. A buffer,
When the received data is received, the identification information of all the plurality of buffers in the message buffer and the identification information obtained from the mask information are compared with the identification information of the received data, and the identification information of the plurality of buffers matches. In this case, the buffer having the highest priority is selected according to the mask information, and when the overwrite information of the selected buffer indicates that writing is not possible, the selected buffer and other buffers are selected. A control circuit that processes received data without writing data;
A data processing module comprising: 5. The data processing module according to claim 4, wherein the identification information is composed of a plurality of bits, and the mask information is information for masking the predetermined bits of the plurality of bits.   When the first message is stored in the buffer associated with the first address of the message buffer, the buffer associated with the first address cannot be overwritten, and the identifier of the first message When the second message to which the same identifier is assigned is received, the buffer associated with the second address, which has a lower priority than the first address, has the same identifier and can be overwritten. A message receiving method of a data processing module, wherein the second message is not stored in a buffer associated with an address. 7. The message reception of the data processing module according to claim 6 , wherein the identifier of the buffer related to the second address is masked by mask information, and the masked identifier is the same as the identifier of the second message. Method.

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