JP6654097B2 - Communication control device and communication control method - Google Patents

Description

  The present invention relates to a communication control device and a communication control method.

  Various types of semiconductor integrated circuit devices (hereinafter referred to as "ICs") communicate with each other by means of a circuit for communicating with each other. A serial bus for transferring data is included. These communications may fail due to disturbances such as circuit failure or noise. The speed of communication and the frequency of communication increase the risk of communication failure.

  In order to remedy poor connection between ICs, there has been proposed a method of providing two wiring paths in advance (for example, Patent Document 1). Patent Literature 1 discloses a method in which, when a connection failure is detected in one of two paths during a connection test, the connection is changed to the other path (redundant wiring).

JP 2003-309183 A

  As the performance of ICs and the speed of communication increase, communication between ICs, which are the core of control devices, requires high reliability. Even in the existing technology, it is possible to detect and notify a communication abnormality due to garbled data, poor connection, or the like. However, in the existing technology, there is a method of detecting a communication abnormality caused by the above-described factors, but there is no method of continuing communication without losing communication data at the time of occurrence of the abnormality. Therefore, for example, in an application in which data loss must be minimized, it cannot be a means for solving the problem.

  On the other hand, there is conceivable a means for retransmitting the same data as when communication failed after detecting a communication abnormality by the conventional technique. However, in an environment where communication is performed at a non-fixed period, a communication delay corresponding to retransmission occurs. Further, in an environment where communication is performed at a fixed period, if communication data to be retransmitted falls within the fixed period, data loss does not occur. However, if communication data does not fall within the fixed period, data loss of at least one period cannot be avoided.

  For example, in the method of Patent Document 1, it is possible to detect a circuit connection failure before starting communication and change the route, but an abnormality occurred during communication (particularly, an abnormality other than a connection failure before the communication starts). A problem arises in that it is not possible to deal with

  The present invention has been made in view of the above problems, and provides a communication control device and a communication control method capable of continuing continuous communication without causing data loss even when an abnormality occurs during communication. I do.

  For example, in order to solve the above-described problem, a configuration described in the claims is adopted. The present application includes a plurality of means for solving the above-described problems. For example, the present invention includes at least a first IC and a second IC, and the first IC and the second IC Wherein the first IC and the second IC are interconnected by a first communication path and a second communication path for redundancy, and wherein the first IC and the second IC are interconnected by a first communication path and a second communication path for redundancy. A communication control device is provided wherein the first IC transmits the same data to the second IC using the first communication path and the second communication path.

  According to another example, an apparatus in which a first IC and a second IC capable of programming the contents are interconnected by a first communication path and a second communication path for redundancy. Is provided. The communication control method includes a transmitting step in which the first IC transmits the same data to the second IC using the first communication path and the second communication path. A first determining step of determining whether the first data received from the first communication path is normal, and the second IC determining that the second data received from the second communication path is normal. And the second IC is determined to be normal in the first determination step or the first data determined to be normal in the first determination step. Using the second data, and a response step in which the second IC transmits response data to the first IC.

  According to the present invention, even when an abnormality occurs during communication, continuous communication can be continued without causing data loss. Further features related to the present invention will become apparent from the description of the present specification and the accompanying drawings. Problems, configurations, and effects other than those described above will be clarified by the following description of the embodiments.

1 is a schematic diagram of a communication control device according to a first embodiment of the present invention. FIG. 2 is a schematic diagram of an internal configuration of a programmable IC. 9 is a flowchart when data is received from a first communication path in a receiving IC. 9 is a flowchart when data is received from a second communication path in a receiving IC. FIG. 4 is a communication operation sequence diagram according to the first embodiment of the present invention. FIG. 11 is a communication operation sequence diagram according to the second embodiment of the present invention. FIG. 13 is a communication operation sequence diagram in Embodiment 3 of the present invention. FIG. 9 is a schematic diagram of a communication control device according to a fourth embodiment of the present invention. It is a schematic diagram of a communication control device according to a fifth embodiment of the present invention. It is a schematic diagram of a communication control device according to a sixth embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The accompanying drawings show specific embodiments in accordance with the principles of the present invention, but these are for understanding of the present invention and are not used to limit the present invention in any way. .

  The following embodiment relates to a circuit in which semiconductor integrated circuit elements (ICs) communicate with each other, and is particularly suitable for a configuration using a plurality of programmable ICs in the same communication system.

  The communication control device according to the present embodiment includes a circuit board on which two or more ICs are connected via a plurality of communication paths. An IC is an IC whose contents can be programmed (hereinafter, referred to as a “programmable IC”). The communication control device generates a data loss even when a communication data error, a communication path connection failure, a disconnection, or the like (hereinafter, these are simply referred to as “communication errors”) occur at the start of communication or during communication. And a redundant communication path for continuing continuous communication. Two or more programmable ICs incorporate programs for controlling them.

  Programmable ICs include microcomputers (hereinafter, microcomputers), Programmable Logic Devices (hereinafter, PLDs) such as Complex Programmable Logic Devices (hereinafter, CPLDs), and Field Programmable Gate Arrays (hereinafter, FPGAs). A parallel bus or a serial bus is used as a communication path for interconnecting these programmable ICs.

[Example 1]
FIG. 1 shows a schematic diagram of the simplest communication control device of the present invention. The communication control device includes a first programmable IC (1-a) and a second programmable IC (1-b). The first programmable IC (1-a) and the second programmable IC (1-b) are mutually connected by a first communication path 2 and a second communication path 3-1 on a one-to-one basis. I have. Here, the second communication path 3-1 is a redundant path, and in this example, there is one redundant path. One of the first programmable IC (1-a) and the second programmable IC (1-b) transmits the same data within one period to the first communication path 2 and the second communication path. Transmit via 3-1. The other of the first programmable IC (1-a) and the second programmable IC (1-b) is connected to the first communication path 2 and the second communication path 3-1 within the above-mentioned cycle. Receive data from Here, the period is a period from when one programmable IC transmits data to when the other IC receives response data from the other programmable IC.

  FIG. 2 is a schematic diagram of the internal configuration of the programmable IC, and shows the internal configurations of the first programmable IC (1-a) and the second programmable IC (1-b) of FIG. In FIG. 2, the programmable IC 20 is one of a first programmable IC (1-a) and a second programmable IC (1-b), and the external device 27 connects the other IC. The illustration is omitted.

  The programmable IC 20 includes a communication processing unit 21 and an IC internal bus 22. The communication processing unit 21 includes a first communication processing unit 23, a second communication processing unit 24, a communication data acquisition unit 25, and a transmission data processing unit 26.

  The first communication processing unit 23 is a processing unit that transmits and receives data via the first communication path 2. The second communication processing unit 24 is a processing unit that transmits and receives data via the second communication path (redundant path) 3-1. The communication data acquisition unit 25 acquires data received by the first communication processing unit 23 or data received by the second communication processing unit 24. The transmission data processing unit 26 creates data to be transmitted from the first communication processing unit 23 and data to be transmitted from the second communication processing unit 24, and sends the data to the first and second communication processing units 23 and 24. Output.

  FIG. 3 is a flowchart when the receiving IC receives data from the first communication path 2. The processing of FIG. 3 will be described using the functional blocks of FIG. Hereinafter, an example will be described in which the second programmable IC (1-b) receives data from the first programmable IC (1-a).

(Step 301)
When the second programmable IC (1-b) receives data from the first programmable IC (1-a) via the first communication path 2, the first communication processing unit 23 Perform a consistency check. The checking method here uses an existing technology such as a parity check or a CRC check.

(Step 302)
The first communication processing unit 23 determines whether the data received from the first communication path 2 is normal or abnormal based on the result of the above-described consistency check. The first communication processing unit 23 outputs the received data and the determination result to the communication data acquisition unit 25. If the received data is normal, the process proceeds to step 303. On the other hand, if the received data is abnormal, the process proceeds to step 304.

(Step 303)
The communication data acquisition unit 25 uses the data received from the first communication path 2 as normal data. The communication data acquisition unit 25 stores the received data in a data storage unit (not shown), and ends the reception processing. As an example, step 303 is executed at the timing of step 404 in FIG. 4 described below. When the communication data acquisition unit 25 adopts normal data received from the first communication path 2 without waiting for reception from the second communication path 3-1, step 404 in FIG. 4 is omitted. You may.

(Step 304)
If the data received from the first communication path 2 is abnormal, the communication data acquisition unit 25 waits for data reception from the second communication path 3-1. When data is received, the process proceeds to the flow of FIG. If no data is received, the process proceeds to step 305.

(Step 305)
In the present embodiment, if no data is received from the second communication path 3-1, the process is suspended while waiting for data, so a timeout is set. The communication data acquisition unit 25 determines whether the waiting time for receiving data from the second communication path 3-1 has passed a prescribed time. If the specified time has elapsed, the communication data acquisition unit 25 determines that a timeout has occurred, and proceeds to step 306. On the other hand, if the specified time has not passed, the process waits for data reception from the second communication path 3-1.

(Step 306)
If a timeout has occurred, the communication data acquisition unit 25 notifies the system of the abnormality, and ends the reception processing. Although not shown, a timeout may be similarly set when data is not received from the first communication path 2 even after a prescribed time has elapsed.

  FIG. 4 is a flowchart when the receiving IC receives data from the second communication path 3-1. The processing of FIG. 4 will be described using the functional blocks of FIG.

(Step 401)
When the second programmable IC (1-b) receives data from the first programmable IC (1-a) via the second communication path 3-1, the second communication processing unit 24 Perform a data integrity check. The checking method here uses an existing technology such as a parity check or a CRC check.

(Step 402)
The second communication processing unit 24 determines whether the data received from the second communication path 3-1 is normal or abnormal based on the result of the above-described consistency check. The second communication processing unit 24 outputs the received data and the determination result to the communication data acquisition unit 25. If the received data is normal, the process proceeds to step 403. On the other hand, if the received data is abnormal, the system notifies the system of the abnormality and ends the receiving process.

(Step 403)
The communication data acquisition unit 25 determines whether the data received from the first communication path 2 is normal or abnormal. If the data received from the first communication path 2 is normal, the process proceeds to step 404. On the other hand, if the data received from the first communication path 2 is abnormal, the process proceeds to step 405.

(Step 404)
The communication data acquisition unit 25 does not use the data received from the second communication path 3-1. As an example, step 303 in FIG. 3 is executed at this timing. In this case, the communication data acquisition unit 25 uses the data received from the first communication path 2 as normal data. The communication data acquisition unit 25 stores the data received from the first communication path 2 in a data storage unit (not shown), and ends the reception processing. Note that, as described above, this step may be omitted.

(Step 405)
The communication data acquisition unit 25 uses the data received from the second communication path 3-1 as normal data. The communication data acquisition unit 25 stores the received data in a data storage unit (not shown), and ends the reception processing.

  According to the above configuration, it is possible to add redundancy to the conventional one-system communication system and improve the reliability.

  In order to realize this embodiment, both the transmitting side and the receiving side need to be programmable ICs. As described above, the programmable IC includes a device such as a microcomputer or a PLD. In this embodiment, a case where the programmable IC is configured by a PLD will be described.

  Since the PLD can be designed in a wide range from pin assignment to internal logic, for example, the bus of the first communication path 2 and the second communication path 3-1 for redundancy can have the same specification. Therefore, the transmitting IC can transmit data to the same address at substantially the same time using each of the first communication path 2 and the second communication path 3-1. When the receiving IC is also a PLD, the receiving IC receives data using the separate pins on the first communication path 2 and the second communication path 3-1 respectively, and the respective signals do not conflict with each other. Can be processed. The PLD can be programmed to perform the above processing.

  FIG. 5 is a communication operation sequence diagram of the present embodiment, and is a communication operation sequence diagram when both the first programmable IC (1-a) and the second programmable IC (1-b) are PLDs. is there. FIG. 5 shows a communication status at a fixed period.

  When the programmable IC is a PLD, transmission using the first communication path 2 and transmission using the second communication path 3-1 can be performed at substantially the same timing. At this time, there is a difference in the transmission completion time between the first communication path 2 and the second communication path 3-1 depending on the communication speed of the bus used. In FIG. 5, T is the transmission time of transmission using the first communication path 2, and T 'is the transmission time of transmission using the second communication path 3-1. When the same communication speed is used for the first communication path 2 and the second communication path 3-1, the difference between T and T ′ can be made as close as possible to zero. However, a slight difference occurs depending on factors such as the wiring length of the communication path.

  The first programmable IC (1-a) on the transmitting side transmits the same data using the first communication path 2 and the second communication path 3-1 within one cycle. The second programmable IC (1-b) on the receiving side processes the received data as shown in the flowcharts of FIGS. Thereafter, the second programmable IC (1-b) on the receiving side transmits the response data to the first programmable IC (1-a). At this time, as in the case of transmission, a difference in response time occurs between the first communication path 2 and the second communication path 3-1 depending on the communication speed of the bus used. Reception of all response data is completed at the response time R 'in FIG. As described above, when performing communication at a fixed cycle, it is necessary to match the entire communication cycle with the bus having the slower communication cycle. Therefore, the cycle in this example is a period of the response time R '.

  From the above, it is preferable that the bus specifications and the communication speed of the first communication path 2 and the second communication path 3-1 be as close as possible. As a result, communication overhead can be minimized. In addition, it is preferable that the one having the higher communication speed among the two paths be the first communication path 2 which is the main communication. This makes it possible to reduce the communication time.

  According to the present embodiment, continuous communication can be continued without causing data loss even when a communication error (communication data error, communication path connection failure, disconnection, etc.) occurs at the start of communication or during communication. Therefore, communication reliability can be improved. Further, according to the present embodiment, it is possible to reduce the time loss corresponding to the retransmission time by omitting the retransmission process when communication fails. Further, according to the present embodiment, it is possible to provide a highly reliable communication control device and a communication control method by multiplexing communication paths in an environment where there is a high risk of communication failure such as disturbance of circuit failure or noise.

[Example 2]
FIG. 6 is a communication operation sequence diagram of the present embodiment, in which both the first programmable IC (1-a) and the second programmable IC (1-b) are microcomputers. is there.

  Unlike the sequence diagram of FIG. 5, the sequence diagram of FIG. 6 has two starting points of arrows extending from the first programmable IC (1-a) and the second programmable IC (1-b). This is because, unlike the PLD, the microcomputer cannot perform the same data communication from different pins at the same time, and the task processing inside the microcomputer starts transmission on the first communication path 2 and the second communication path 3-1. This is because a slight difference occurs.

  If the programmable IC is a microcomputer, the buses of the first communication path 2 and the second communication path 3-1 cannot have the same specifications, and data cannot be transmitted simultaneously to the same address. Therefore, in the present embodiment, the programmable IC on the transmitting side transmits the same data to different addresses using the first communication path 2 and the second communication path 3-1 which are buses of different specifications. .

  In the case of the description of the functional block in FIG. 2, the transmission data processing unit 26 of the programmable IC on the transmission side sends the address for the first communication path 2, the second communication path 3-1 Set the address for each. Then, the first communication processing unit 23 and the second communication processing unit 24 each transmit the same data via each path. The programmable IC on the receiving side receives the data transmitted at different addresses via the first communication path 2 and the second communication path 3-1 and receives the data as shown in the flowcharts of FIGS. Process the data.

  According to the present embodiment, even if the first communication path 2 and the second communication path 3-1 have different specifications, the processing of the present invention can be performed. For example, the above configuration is applied to a system of a two-microcomputer system in which two microcomputers are mounted to monitor and monitor each other for the purpose of improving system reliability and safety so that communication between the microcomputers has redundancy. It becomes possible. Further, the reliability of the system can be further improved.

  Although the above-described microcomputer has been described assuming a single core, the present invention is not limited to this. The present invention can be applied to a dual-core microcomputer. In this case, the transmission-side programmable IC can transmit the same data at substantially the same timing without causing a difference in the transmission timing as described above.

[Example 3]
A case will be described in which one programmable IC is a microcomputer and the other programmable IC is a PLD in the same configuration as in the first embodiment. FIG. 7 is a communication operation sequence diagram when the first programmable IC (1-a) is a microcomputer and the second programmable IC (1-b) is a PLD. As an operation, the first embodiment and the second embodiment are combined.

  As described in the second embodiment, when the first programmable IC (1-a) that is a microcomputer transmits data, the first communication path 2 is connected to the first programmable IC (1-a). There is a difference in the transmission timing with the second communication path 3-1. Further, regarding the first programmable IC (1-a), a bus having the same specification cannot be used for the first communication path 2 and the second communication path 3-1. Cannot send.

  The second programmable IC (1-b), which is a PLD, can make the timing of transmitting data to the first communication path 2 and the second communication path 3-1 substantially the same. Unlike the connection between PLDs as in the first embodiment, the same address cannot be accessed simultaneously through different communication paths. For this reason, like the communication conditions between the microcomputers, the second programmable IC (1-b) transmits the same data to different addresses in the first communication path 2 and the second communication path 3-1. Designed to. According to this configuration, the processing of the present invention can be executed even in a communication control device in which a microcomputer and a PLD coexist.

[Example 4]
Regarding the configurations of the first to third embodiments, a form of a communication control device having a plurality of redundant paths will be described. FIG. 8 is a schematic diagram of a communication control device according to the fourth embodiment of the present invention. In contrast to the basic configuration in which a first programmable IC (1-a) and a second programmable IC (1-b) are connected by a first communication path 2 and a second communication path 3-1; It is possible to add as many redundant paths as address ranges or chip select numbers as long as the specifications (1-a) and (1-b) allow. In the example of FIG. 8, a plurality of redundant second communication paths 3-1 to 3-n are provided between the first programmable IC (1-a) and the second programmable IC (1-b). It is provided in.

  When performing periodic communication in this configuration, communication between the first communication path 2 and a plurality of redundant second communication paths 3-1 to 3-n as described in the first to third embodiments. Speed differences need to be taken into account. Therefore, a cycle is set in accordance with the path having the slowest communication speed among the first communication path 2 and the plurality of redundant second communication paths 3-1 to 3-n, and communication is performed in accordance with the cycle. Designed to. Further, the communication processing unit 21 includes communication processing units of the number of added redundant routes (this communication processing unit has the same configuration as the second communication processing unit 24).

  Further, in the case of performing non-fixed-cycle communication in this configuration, the priority may be set from the redundant second communication paths 3-1 to 3-n in ascending order of communication speed. In this case, the programmable IC on the receiving side (for example, the second communication processing unit 24, the communication data acquisition unit 25, etc.) is connected to any of the redundant second communication paths 3-1 to 3-n. When it is determined that the data received from the second communication path is normal, the reception processing (consistency check etc.) is performed on the data received from the plurality of second communication paths 3-1 to 3-n thereafter. May be designed to execute a response process without performing the process. Since the programmable IC on the receiving side can immediately shift to the response processing when normal data is received, the communication time can be reduced.

[Example 5]
Next, a configuration in which three or more programmable ICs are connected will be described. FIG. 9 is a schematic diagram of a communication control device according to the fifth embodiment of the present invention. The communication control device includes a plurality of programmable ICs (1-a), (1-b), (1-c) to (1-n). In this case, the plurality of programmable ICs (1-a), (1-b), (1-c) to (1-n) include a first communication path 2 and one or more second communication paths. 3-1. Each of the plurality of programmable ICs (1-a), (1-b), (1-c) to (1-n) can execute the transmission processing and the reception processing described in the first to fourth embodiments. It is possible.

  As for the connection form, if a plurality of programmable ICs (1-a) to (1-n) are mixed in the same system bus, the first communication path 2 and the second communication path 3 It is possible to minimize the number of communication paths of −1.

[Example 6]
Next, a communication control device in which a programmable IC and a non-programmable IC (an IC whose contents cannot be programmed) coexist will be described. FIG. 10 is a schematic diagram of a communication control device according to the sixth embodiment of the present invention.

  The present invention cannot be applied to a device other than a programmable IC, but the programmable IC may be connected to a memory device such as an SRAM or a FlashROM, and various types of ICs using a parallel bus or a serial bus. is there. In this case, the non-programmable IC is connected to one communication path. It is possible to design the communication path for non-programmable ICs separately from the communication path for programmable ICs of the present invention.However, this increases the wiring area of the board. Is not desirable in the case of severe restrictions.

  Therefore, as shown in FIG. 10, the target device (the non-programmable IC 4) is arranged on the first communication path 2, and the device which needs redundancy (in FIG. 10, the first and second programmable ICs). Only (1-a) and (1-b)) are mutually connected by the first communication path 2 and the second communication path 3-1. According to this configuration, the non-programmable IC 4 is connected to the first and second programmable ICs (1-a) and (1-b) in a conventional manner, and the second communication path 3-1 is connected. Communication can be performed without awareness.

  Hereinafter, the effects of the first to sixth embodiments will be described. At present, with high performance of ICs and high speed of communication, high reliability is required for communication between ICs which are the core of the control device. Conventionally, in a configuration in which a plurality of programmable ICs are used in the same communication system, continuous communication cannot be continued without causing data loss even when an abnormality occurs during communication.

  In order to solve the above-mentioned problem, the communication control device of the above embodiment includes two or more programmable ICs connected to each other, a first communication path 2 for connecting the programmable ICs to each other, And one or more second communication paths (3-1 to 3-n) for redundancy for interconnecting various ICs. In this configuration, the transmitting-side programmable IC transmits the same communication data to the receiving-side programmable IC in the first communication path and the one or more redundant second communication paths. In the case of communication at a fixed period, the programmable IC on the transmitting side transmits communication data of the same content to the programmable IC on the receiving side within a certain period.

  The receiving-side programmable IC checks the validity of data received from the first communication path and one or more second communication paths, and uses normal data. For example, if an error is detected in the communication data from the first communication path, the programmable IC on the receiving side may select a normal one from among the data received from the one or more second communication paths for redundancy. Is adopted. Thereby, communication can be continued without data loss.

  In the event of a connection failure of the communication path or disconnection of the communication path, the programmable IC on the receiving side checks the validity of the data and performs the redundancy Normal data can be adopted from the data received from one or more second communication paths. Thus, communication can be continued without data loss even when a connection failure of the communication path occurs or a disconnection of the communication path occurs.

  Further, processing when data does not completely arrive from the communication path will be described. When the communication is performed in an irregular cycle, the programmable IC on the receiving side receives the data from one or more second communication paths for redundancy, but receives the data from the first communication path. When no data is received from, the first communication path may be determined to be a connection failure or disconnection. At this time, the programmable IC on the receiving side adopts normal data from the data received from the redundant second communication path. Thereby, communication can be continued without data loss. In addition, when communication is performed at regular intervals, setting a timeout allows the programmable IC on the receiving side to detect a connection failure or disconnection in the communication path when no data is received within a certain time. It may be determined. At this time, as the programmable IC on the receiving side, normal data is adopted from the data received from the redundant second communication path. Thereby, communication can be continued without data loss.

  By providing a plurality of second communication paths for redundancy as in the above configuration, even if a communication error occurs in any of the communication paths for redundancy in addition to the first communication path for normal use, the first By performing the same processing as in the case where a communication abnormality has occurred in the communication path, communication can be continued without data loss.

  The present invention is not limited to the embodiments described above, and includes various modifications. The above embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described above. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment. Further, the configuration of one embodiment can be added to the configuration of another embodiment. Further, for a part of the configuration of each embodiment, another configuration can be added, deleted, or replaced.

  In the above-described embodiment, the control lines and the information lines are considered to be necessary for the description, and do not necessarily indicate all the control lines and the information lines on the product. All components may be interconnected.

1-a, 1-b, 1-c to 1-n ... Programmable IC
2... First communication paths 3-1 to 3-n... Second communication paths (redundant communication paths)
4 ... non-programmable IC
Reference Signs List 21 communication processing unit 22 IC internal bus 23 first communication processing unit 24 second communication processing unit 25 communication data acquisition unit 26 transmission data processing unit 27 external device

Claims (6)

At least a first IC and a second IC,
The first IC and the second IC are ICs whose contents can be programmed,
The first IC and the second IC are interconnected by a first communication path and a redundant second communication path;
The first communication path has a higher communication speed than the second communication path,
The first IC transmits the same data to the second IC using the first communication path and the second communication path within a certain period;
When the transmission using the first communication path and the transmission using the second communication path are performed at the same timing, the cycle is such that the first IC uses the second communication path. sending data Te, Ri period der from the second IC to receive a response using said second communication path,
When the transmission using the second communication path is performed after the transmission using the first communication path is performed, the cycle is such that the first IC uses the first communication path. Te transmitting data, Ru period der from the second IC to receive a response by using the second communication path communication control device. The communication control device according to claim 1,
The communication control device, wherein the second IC terminates a reception process when the second IC does not receive data from the first communication path or the second communication path within a predetermined time. The communication control device according to claim 1,
It further includes a third IC that cannot program its contents,
A communication control device in which the third IC is connected only to the first communication path. A communication control method in a device in which a first IC and a second IC whose contents can be programmed are interconnected by a first communication path and a second communication path for redundancy,
The first communication path has a higher communication speed than the second communication path,
A transmitting step in which the first IC transmits the same data to the second IC using the first communication path and the second communication path within a certain period;
A first determination step in which the second IC determines whether the first data received from the first communication path is normal;
A second determination step in which the second IC determines whether the second data received from the second communication path is normal;
A use step in which the second IC uses the first data determined to be normal in the first determination step or the second data determined to be normal in the second determination step; ,
A response step in which the second IC transmits response data to the first IC;
Including
When the transmission using the first communication path and the transmission using the second communication path are performed at the same timing, the cycle is such that the first IC uses the second communication path. sending data Te, Ri period der from the second IC to receive a response using said second communication path,
When the transmission using the second communication path is performed after the transmission using the first communication path is performed, the cycle is such that the first IC uses the first communication path. sending data Te, Ru period der from the second IC to receive a response using said second communication path,
Communication control method. The communication control method according to claim 4,
The second communication path is plural,
The using step includes:
When it is determined in the first determination step that the first data is normal, the first data is used,
When it is determined in the first determination step that the first data is abnormal, out of the plurality of second data received from the plurality of second communication paths, the first data is determined to be normal in the second determination step. A communication control method using data determined to be present. The communication control method according to claim 4,
A communication control method further comprising terminating a reception process when the second IC does not receive data from the first communication path or the second communication path after a predetermined time has elapsed.

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