关于DSP28379D的CAN通信问题

我根据TI给出的can-loopback例程，然后把IO口改掉，环回模式是对的，之后把环回模式 // Enable test mode and select external loopback HWREG(CANA_BASE + CAN_O_CTL) |= CAN_CTL_TEST; HWREG(CANA_BASE + CAN_O_TEST) = CAN_TEST_EXL;给注释掉，波特率也设定好了，连接一个CAN分析仪后，发现dsp的数据不能发送出去，请问还需要修改其他地方嘛？这是我的程序，十分感谢各位前辈的指导。

main(void){ tCANMsgObject sTXCANMessage; tCANMsgObject sRXCANMessage; // Step 1. Initialize System Control: InitSysCtrl(); // Step 2. Initialize GPIO: InitGpio(); //GPIO70 - CANRXA GPIO_SetupPinMux(17, GPIO_MUX_CPU1, 2); //GPIO71 - CANTXA GPIO_SetupPinMux(12, GPIO_MUX_CPU1, 2); GPIO_SetupPinOptions(17, GPIO_INPUT, GPIO_ASYNC); GPIO_SetupPinOptions(12, GPIO_OUTPUT, GPIO_PUSHPULL); // Initialize the CAN controller CANInit(CANA_BASE); // Setup CAN to be clocked off the M3/Master subsystem clock CANClkSourceSelect(CANA_BASE, 0); CANBitRateSet(CANA_BASE, 200000000, 50000); // Step 3. Clear all interrupts and initialize PIE vector table: // Disable CPU interrupts DINT; InitPieCtrl(); // Disable CPU interrupts and clear all CPU interrupt flags: IER = 0x0000; IFR = 0x0000; InitPieVectTable(); // Enable test mode and select external loopback // HWREG(CANA_BASE + CAN_O_CTL) |= CAN_CTL_TEST; // HWREG(CANA_BASE + CAN_O_TEST) = CAN_TEST_EXL; // Enable the CAN for operation. CANEnable(CANA_BASE); // Initialize the message object that will be used for sending CAN // messages.The message will be 4 bytes that will contain an incrementing // value.Initially it will be set to 0. *(unsigned long *)ucTXMsgData = 0; sTXCANMessage.ui32MsgID = 1; // CAN message ID - use 1 sTXCANMessage.ui32MsgIDMask = 0; // no mask needed for TX sTXCANMessage.ui32Flags = MSG_OBJ_TX_INT_ENABLE;// enable interrupt on TX sTXCANMessage.ui32MsgLen = sizeof(ucTXMsgData); // size of message is 4 sTXCANMessage.pucMsgData = ucTXMsgData; // ptr to message content // Initialize the message object that will be used for recieving CAN // messages. *(unsigned long *)ucRXMsgData = 0; sRXCANMessage.ui32MsgID = 1; // CAN message ID - use 1 sRXCANMessage.ui32MsgIDMask = 0; // no mask needed for TX sRXCANMessage.ui32Flags = MSG_OBJ_NO_FLAGS; sRXCANMessage.ui32MsgLen = sizeof(ucRXMsgData); // size of message is 4 sRXCANMessage.pucMsgData = ucRXMsgData; // ptr to message content // Setup the message object being used to receive messages CANMessageSet(CANA_BASE, 5, &sRXCANMessage, MSG_OBJ_TYPE_RX); // Enter loop to send messages.A new message will be sent once per // second.The 4 bytes of message content will be treated as an unsigned // long and incremented by one each time. for(;;) { // Send the CAN message using object number 1 CANMessageSet(CANA_BASE, 1, &sTXCANMessage, MSG_OBJ_TYPE_TX); // Now wait 1 second before continuing DELAY_US(1000*1000); // Get the receive message CANMessageGet(CANA_BASE, 5, &sRXCANMessage, true); // Ensure the received data matches the transmitted data if((*(unsigned long *)ucTXMsgData) != (*(unsigned long *)ucRXMsgData)){ asm(" ESTOP0"); } // Increment the value in the transmitted message data. (*(unsigned long *)ucTXMsgData)++; asm(" ESTOP0"); }}