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器件型号：TMS320F280025C 主题：C2000WARE 中讨论的其他器件
工具/软件：
大家好、
我在利用 TX 中断线路传输 CAN 总线消息时遇到了一些问题。
问题如下：
为了传输一些信息、我将邮箱设置为 8 字节长 (DLC = 8)。
然后、在一个简单的 while 循环中、我希望发送 5-6 条连续的 CAN 总线消息、每个消息都包含不同的数据。
通过使用 CAN 分析仪嗅探总线、我注意到第一条消息发送时的 DLC 等于 8、而所有后续消息都有 DLC = 2。
我不能真正理解它（我粘贴在屏幕截图下面）。
我附加了一个代码片段、供您深入探究。
如果您有任何线索、请告诉我。
谢谢 
Elia
// WHILE LOOP
// I receive a serial message and based on it I decide which message I want to send
// WritePkt has as arguments (in order):
// - canbus message to be sent
// - serial message from which information is retrieved
// - length of the canbus message (in order to know which mailbox I should use)
// - pointer to the serial buffer, in order to be aligned with the information I want to extract
while(serial_Rx[ptr_rx] != '\r'){ // indica la fine del messaggio seriale (completo)
if(serial_Rx[ptr_rx] == '\n'){ // indica l'inizio del sottomessaggio seriale (pacchetto)
pkt_id = serial_Rx[ptr_rx+1];
switch(pkt_id){
case WRITE_MULTIPLE_REGS:
WritePkt(WR_multiple, serial_Rx, sizeof(WR_multiple), &ptr_rx);
break;
case WRITE_PART_NUMBER_1:
WritePkt(part_number1, serial_Rx, sizeof(part_number1), &ptr_rx);
break;
case WRITE_PART_NUMBER_2:
WritePkt(part_number2, serial_Rx, sizeof(part_number2), &ptr_rx);
break;
case WRITE_PART_NUMBER_3:
WritePkt(part_number3, serial_Rx, sizeof(part_number3), &ptr_rx);
break;
case WRITE_PART_NUMBER_4:
WritePkt(part_number4, serial_Rx, sizeof(part_number4), &ptr_rx);
break;
case WRITE_PART_NUMBER_5:
WritePkt(part_number5, serial_Rx, sizeof(part_number5), &ptr_rx);
break;
}
DELAY_US(200);
}
}
// WRITE PKT
void WritePkt(char *buffer_can, char *buffer_serial, uint16_t size_buffer_can, uint16_t *ptr){
//uint16_t messageObj;
// funzione che prende in ingresso i due buffer e restituisce il ptr_rx aggiornato
// uint16_t CAN_pkt(buffer_can, buffer_serial);
buffer_can[0] = buffer_serial[*ptr+1];
buffer_can[1] = buffer_serial[*ptr+2] + ADDR_OFFSET;
// 6 byte per data
memcpy(&buffer_can[2], &buffer_serial[*ptr+3], (size_buffer_can/(sizeof(buffer_can[0]))-2));
// capisco quale tipo di messaggio inviare dalla DLC (ovvero la lunghezza del buffer in ingresso)
switch(size_buffer_can){
case DLC_2:
sendCANMessage(CAN_TX_READ, buffer_can);
//messageObj = CAN_TX_READ;
break;
case DLC_4:
sendCANMessage(CAN_TX_FEED, buffer_can);
//messageObj = CAN_TX_FEED;
break;
case DLC_8:
sendCANMessage(CAN_TX_WRITE, buffer_can);
//messageObj = CAN_TX_WRITE;
break;
}
*ptr += 1 + size_buffer_can/(sizeof(buffer_can[0]));
//return messageObj;
}
// ISR TX CANBUS
// Devo riuscire a farlo funzionare!
__interrupt void cana_tx_isr(void){
dbg.can_tx++;
while(CanaRegs.CAN_IF1CMD.bit.Busy){}
// LOCK FEEDER
if((CanaRegs.CAN_IPEN_21 && (1 << (CAN_TX_LOCK-1))) && (CanaRegs.CAN_INT.bit.INT1ID == CAN_TX_LOCK)){
GpioDataRegs.GPATOGGLE.bit.GPIO31 = 1;
}
// WRITE HANDLING
else if((CanaRegs.CAN_IPEN_21 && (1 << (CAN_TX_WRITE-1))) && (CanaRegs.CAN_INT.bit.INT1ID == CAN_TX_WRITE)){
GpioDataRegs.GPBTOGGLE.bit.GPIO34 = 1;
}
// READ HANDLING
else if((CanaRegs.CAN_IPEN_21 && (1 << (CAN_TX_READ-1))) && (CanaRegs.CAN_INT.bit.INT1ID == CAN_TX_READ)){
GpioDataRegs.GPATOGGLE.bit.GPIO31 = 1;
}
// FEED HANDLING
else if((CanaRegs.CAN_IPEN_21 && (1 << (CAN_TX_FEED-1))) && (CanaRegs.CAN_INT.bit.INT1ID == CAN_TX_FEED)){
GpioDataRegs.GPATOGGLE.bit.GPIO31 = 1;
}
CanaRegs.CAN_IF1CMD.bit.Control = 1;
CanaRegs.CAN_IF1CMD.bit.TXRQST = 0;
//CanaRegs.CAN_IF1CMD.bit.ClrIntPnd = 1;
CanaRegs.CAN_GLB_INT_CLR.bit.INT1_FLG_CLR = 1;
PieCtrlRegs.PIEACK.bit.ACK9 = 1;
}
