JP2012142646A - Vehicle communication device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inexpensively correspond to the increase of reception IDs (recognition information).SOLUTION: A buffer part 3 is constituted by multiple buffer units 3a, 3b which are divided into multiple areas m1-m32 for each piece of identification information. The prescribed buffer unit 3a is connected to a transmission/reception circuit part 4 via a transmission terminal part t and a reception terminal part r, thereby to hold transmission data in at least a part of the areas. The other buffer unit 3b is set to be exclusive for reception and connected to the transmission/reception circuit part 4 via its reception terminal part, thereby to increase effective reception IDs.

Description

  The present invention relates to a vehicular communication apparatus such as various devices in a vehicle connected by a communication bus, and more particularly to a novel configuration that can cope with an increase in received identification information at a low cost.

  2. Description of the Related Art Conventionally, various ECUs or the like in an automobile exchange information by being connected by a network of a serial communication protocol represented by CAN (Controller Area Network) or LIN (Local Interconnect Network).

  For example, in the case of a CAN vehicle communication apparatus, transmission data and reception data are exchanged between microcomputers such as ECUs with IDs (recognition information) for recognizing devices and the like added. At that time, for transmission / reception of data, a vehicle communication device provided with a buffer unit for transmission / reception and a transmission / reception circuit unit is used (see, for example, Patent Document 1 (paragraphs [0003]-[0006], FIG. 1)). .

  FIG. 2 shows a schematic basic configuration of the above-described vehicle communication device 100. The buffer unit 102 in which data is read and written by the CPU 101 is, for example, 32 areas m1 for each ID if the total number of transmission / reception IDs is 32. The transmission / reception circuit unit 104 is provided in the subsequent stage, which is formed by an IC of the buffer unit 103 of one channel divided (divided) into .about.m32.

  In the buffer unit 103, IDs assigned to the areas m1 to m32 are determined, and the transmission data of each ID from the CPU 101 is held in the corresponding transmission ID area of the buffer unit 103, and then the buffer unit 103 The signal is transmitted from the transmission terminal unit (transmission port) t to the transmission / reception circuit unit 104, converted into a CAN signal by the transmission / reception circuit unit 104, and transmitted to the CAN communication bus 105 that constructs the network. Each CAN reception signal (transmission signal of another device) of the communication bus 105 is converted into a reception ID and reception data that can be handled by the CPU 101 by the transmission / reception circuit unit 104, and the converted reception ID and reception data are Then, the data is sent from the transmission / reception circuit unit 104 to the reception terminal unit (reception port) r of the buffer unit 103, and the received data is captured and held in the corresponding reception ID area of the buffer unit 103. Read the received data.

JP 2009-282612 A

  In this type of vehicle communication device, as described above, the total number of transmission / reception IDs that can be held in the one-channel buffer unit 103 of the buffer unit 102 is fixed at 32, for example, so the number of in-vehicle devices (ECUs) increases. If the reception ID increases and one buffer unit 103 cannot cover it, the buffer unit 102 may be formed as a commercially available two-channel buffer unit. In this case, however, transmission data competes between channels. If the transmission data of the buffer units of both channels are input to the same transmission / reception circuit unit at the same time, a signal level short circuit occurs and transmission is impossible. Therefore, a transmission / reception circuit unit is provided for each channel.

  FIG. 3 shows a configuration in which the buffer unit 102 of the conventional apparatus is added to buffer units 103a and 103b of two channels (hereinafter, one of the two channels is called channel A and the other is called channel B).

  In this case, the transmission terminal part t and the reception terminal part r of the buffer unit 103a of channel A are connected to the transmission / reception circuit part 104a of the channel, and the transmission terminal part t and reception terminal part r of the buffer unit 103b of channel B are the channel. The transmission / reception circuit units 104 a and 104 b are connected to the communication bus 105.

  In the buffer units 103a and 103b, for example, a part (for example, half) of 32 areas m1 to m32 is a reception ID area, and these areas are assigned to different reception IDs. Therefore, the number of IDs that can be received in the buffer unit 102 is doubled as compared with the case where any one of the buffer units 103a and 103b is configured.

  However, if the transmission / reception circuit units 104a and 104b are added as the buffer units 103a and 103b of the buffer unit 102 are increased based on the increase of the reception ID as shown in FIG. 3, there is a problem that the cost is greatly increased.

  An object of the present invention is to cope with an increase in received ID (recognition information) at a low cost.

  In order to achieve the above object, the vehicular communication device of the present invention is made paying attention to the fact that the received data does not compete, and the transmission data held in the buffer unit is attached with identification information (ID). A communication device for a vehicle that transmits to the communication bus from the transmission / reception circuit unit, receives the reception data of the communication bus by the transmission / reception circuit unit, and holds the received data in the buffer unit. Formed by a plurality of buffer units divided into a plurality of areas, the predetermined buffer unit, at least a part of the area is set to hold transmission data, the transmission terminal unit, the reception terminal unit is connected to the transmission / reception circuit unit, The remaining buffer units are characterized in that each area is set to hold received data and the receiving terminal section is connected to the transmitting / receiving circuit section. (Claim 1).

  According to the first aspect of the present invention, the data of each transmission ID is held in a partial area of a predetermined buffer unit of the buffer unit, and then sent from the transmission terminal unit to the transmission / reception circuit unit to the communication bus. Since it is transmitted, a plurality of transmission data do not compete.

  Next, the data of each reception ID of the communication bus is received in order by the transmission / reception circuit unit, and if the remaining area of the predetermined buffer unit of the buffer unit is an area of the reception ID, the transmission / reception circuit unit transmits the data to the predetermined buffer. A branch is input to the receiving terminals of the unit and the remaining buffer units. If the entire area of the predetermined buffer unit is a transmission ID area, a branch input is made only to the receiving terminals of the remaining buffer units. At this time, since the same received data is branched and input to each buffer unit, a level short-circuit of the received data does not occur. Then, the reception data of the reception ID is held in the corresponding reception ID area of each buffer unit, and the number of reception IDs that can be held in the buffer unit is increased as compared with the case of only the predetermined buffer unit.

  In this case, it is not necessary to prepare a transmission / reception circuit unit for each buffer unit, and only one transmission / reception circuit unit may be provided. The number of reception data buffer units may be increased as the number of received IDs increases, and the configuration is inexpensive. Thus, it is possible to cope with an increase in reception ID.

It is a block diagram of one embodiment of a communication device for vehicles of the present invention. It is a block diagram of the conventional apparatus which provided the buffer unit of 1 channel in the buffer part. It is explanatory drawing at the time of providing the buffer unit of 2 channels in the buffer part of the conventional apparatus of FIG.

  Next, in order to describe the present invention in more detail, an embodiment of the present invention will be described in detail with reference to FIG.

  FIG. 1 shows a block connection diagram of the vehicle communication device 1 of the present embodiment. A buffer unit 3 from / to which data is read / written by the CPU 2 is divided (segmented) into 32 areas m1 to m32 for each ID. Buffer unit 3a and channel B buffer unit 3b.

  In the buffer unit 3a, a part of the 32 storage areas m1 to m32 (for example, the storage areas m1 to m16) is set to hold transmission data, and the transmission terminal part t is connected to the transmission / reception circuit part 4.

  Further, the remaining storage areas (for example, storage areas m17 to m32) of the buffer unit 3a and the 32 storage areas m1 to m32 of the buffer unit 3b of the channel B are set to hold reception data, and the reception terminals of the buffer unit 3a The unit r is connected to the transmission / reception circuit unit 4, and for example, the buffer unit 3 b is connected to the buffer terminal 3 b via the branch line Lb for extension in the middle of the signal line Lr that connects the reception terminal unit r of the buffer unit 3 a to the transmission / reception circuit unit 4. A receiving terminal r is connected. The transmission / reception circuit unit 4 is connected to a CAN communication bus 5.

  The remaining storage areas (for example, the storage areas m17 to m32) of the buffer unit 3a and the 32 storage areas m1 to m32 of the buffer unit 3b of the channel B are set to areas of different reception IDs, and the communication bus 5 The received data of each received ID is branched and input to the receiving terminal section r of the buffer units 3a and 3b via the transmission / reception circuit section 4, and held in the corresponding received ID area of the buffer units 3a and 3b. The

  In this case, by adding the buffer unit 3b as a reception-only buffer unit, the reception ID area of the buffer unit 3 is changed from, for example, 16 areas of the original buffer unit 3a without affecting transmission data. , Newly increase 32.

  Since the buffer unit 3b is added as a reception-only buffer unit, the reception terminal section r of the buffer unit 3b need only be connected to the transmission / reception circuit section 4 via the branch line Lb for expansion. Therefore, it is possible to cope with an increase in reception ID at a very low cost. When the reception ID further increases, an additional buffer unit dedicated to reception similar to the buffer unit 3b is added to the buffer unit 3, and the reception terminal unit r is connected via a branch line similar to the branch line Lb. The transmitter / receiver circuit unit 4 may be connected.

  Therefore, in the case of this embodiment, when the reception ID increases and the buffer unit 3 cannot be supported by the buffer unit 3a of one channel, the buffer unit dedicated to reception of another channel without adding a transmission / reception circuit unit. By simply adding 3b to the buffer unit 3, it is possible to cope with a low cost. If a buffer unit dedicated to reception similar to the buffer unit 3b is further added to the buffer unit 3, the number of reception IDs can be increased. It can be easily and cost-effectively, and can significantly improve the functionality of CAN communication at low cost.

  The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit thereof. For example, in the above-described embodiment, the buffer unit 3a can be changed. Is shared to hold the transmission ID data (transmission data) and the reception ID data (reception data), but the buffer unit 3a is set as a buffer unit dedicated to transmission, and the reception data is dedicated to reception such as the buffer unit 3b. In this case, the buffer unit 3a can be used by connecting only the transmission terminal portion t to the transmission / reception circuit portion 4. In the buffer unit 3a, the storage areas m1 to m20 may be set to hold transmission data, and the storage areas m21 to m32 may be set to hold reception data. That is, the number of buffer units set to hold transmission data among a plurality of buffer units in a predetermined buffer unit (buffer unit 3a) is set to be larger than the number of buffer units set to hold reception data. Also good. By doing in this way, ID which can be transmitted can be increased, without causing a cost increase.

  Finally, the number of divided areas of each buffer unit 3a, 3b may be any, and the number of divided areas may be different depending on the buffer units 3a, 3b.

  The present invention can be applied not only to a CAN vehicle communication device, but also to a LIN vehicle communication device and the like, and can be applied to various vehicle communication devices.

DESCRIPTION OF SYMBOLS 1 Vehicle communication apparatus 3 Buffer part 3a, 3b Buffer unit 4 Transmission / reception circuit part 5 Communication bus m1-m32 Storage area | region r Reception terminal part t Transmission terminal part

Claims (1)

A vehicle communication apparatus for transmitting transmission data held in a buffer unit with identification information and transmitting the transmission data from a transmission / reception circuit unit to a communication bus, receiving the reception data of the communication bus by the transmission / reception circuit unit, and holding the data in the buffer unit Because
The buffer unit is formed by a plurality of buffer units divided into a plurality of areas for each identification information,
The predetermined buffer unit is configured such that at least a part of the area is set to hold transmission data, a transmission terminal unit, a reception terminal unit is connected to the transmission / reception circuit unit,
Each of the remaining buffer units is set to hold received data, and a receiving terminal portion is connected to the transmitting / receiving circuit portion.

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