以下程序是为了实现can的接收中断，并在接收中断发送数据，如果使能内环测试模式（收与发的Message Identifier一样），是可以进入实现数据收发测试，但是如果设置为外部循环测试或者取消测试模式会出现errorFlag = 1; 这是什么原因，如何解决？
void Init_cana_tr(void)
{
CAN_enableController(CANA_BASE);
CAN_enableGlobalInterrupt(CANA_BASE, CAN_GLOBAL_INT_CANINT0);
//CAN_enableTestMode(CANA_BASE, CAN_TEST_LBACK);
CAN_setupMessageObject(CANA_BASE, 1, 0x20, CAN_MSG_FRAME_STD,CAN_MSG_OBJ_TYPE_TX, 0, CAN_MSG_OBJ_NO_FLAGS,8); //
// Initialize the receive message object used for receiving CAN messages.
// Message Object Parameters:
// Message Object ID Number: 3
// Message Identifier: 0x1
// Message Frame: Standard
// Message Type: Receive
// Message ID Mask: 0x0
// Message Object Flags: Receive Interrupt
// Message Data Length: 8 Bytes (Note that DLC field is a "don't care"
// for a Receive mailbox)
CAN_setupMessageObject(CANA_BASE, 3, 0x20, CAN_MSG_FRAME_STD, CAN_MSG_OBJ_TYPE_RX, 0, CAN_MSG_OBJ_RX_INT_ENABLE,8);
//使能接收中断
*(unsigned long *)ucRXMsgData = 0;
CAN_startModule(CANA_BASE);
}
interrupt void eCANINTA_isr(void)
{
uint32_t status;
//
// Read the CAN interrupt status to find the cause of the interrupt
//
status = CAN_getInterruptCause(CANA_BASE);
// If the cause is a controller status interrupt, then get the status
//
if(status == CAN_INT_INT0ID_STATUS)
{ //默认语句
status = CAN_getStatus(CANA_BASE);
// Check to see if an error occurred.
//
if(((status & ~(CAN_STATUS_TXOK | CAN_STATUS_RXOK)) != 7) &&
((status & ~(CAN_STATUS_TXOK | CAN_STATUS_RXOK)) != 0))
{
// Set a flag to indicate some errors may have occurred.
errorFlag = 1;
}
}
//
// Check if the cause is the transmit message object 1
//
else if(status == 3)
{
//
// Getting to this point means that the TX interrupt occurred on
// message object 1, and the message TX is complete. Clear the
// message object interrupt.
//
CAN_readMessage(CANA_BASE, 3, ucRXMsgData);
CAN_ctr=(ucRXMsgData[0]&4)>>2;
if(CAN_ctr == 1&&ucRXMsgData[7]==0xaa)
{
//EnSystem = ucRXMsgData[0]&1;
EnDrive = (ucRXMsgData[0]&2)>>1;
// T_ctr=(ucRXMsgData[0]&8)>>3;
// //Int_tmp = ucRXMsgData[1];
// Brake_pwm=ucRXMsgData[1]*20;
// SpeedRef_krpm=(float)(ucRXMsgData[3]+ucRXMsgData[2]<<8)*0.1;
// Speed_acc_krpmps=(float)(ucRXMsgData[5]+ucRXMsgData[4]<<8)*0.001;
// T_shell_set=ucRXMsgData[6];
}
CAN_clearInterruptStatus(CANA_BASE, 3); //ID=1
CAN_sendMessage(CANA_BASE,1,8,ucTXMsgData);
// Int_tmp = T_mos * 10; // 转频
// byte_tmp = Int_tmp & 0x00FF;
// ucTXMsgData[1] = byte_tmp; //
// byte_tmp = (Int_tmp & 0xFF00) >> 8;
// ucTXMsgData[0] = byte_tmp; //
// ucTXMsgData[4] += 0x01;
// ucTXMsgData[5] += 0x01;
// ucTXMsgData[6] += 0x01;
// ucTXMsgData[7] += 0x01;
//
// Increment a counter to keep track of how many messages have been
// sent. In a real application this could be used to set flags to
// indicate when a message is sent.
//
txMsgCount++;
//
// Since the message was sent, clear any error flags.
//
errorFlag = 0;
}
//
// Check if the cause is the receive message object 2
//
// else if(status == 2) //不设置发送中断
// {
// //
// // Get the received message
// //
// CAN_readMessage(CANA_BASE, 2, ucRXMsgData);
// //
// // Getting to this point means that the RX interrupt occurred on
// // message object 2, and the message RX is complete. Clear the
// // message object interrupt.
// //
// CAN_clearInterruptStatus(CANA_BASE, 2);
// //
// // Increment a counter to keep track of how many messages have been
// // received. In a real application this could be used to set flags to
// // indicate when a message is received.
// //
// rxMsgCount++;
// //
// // Since the message was received, clear any error flags.
// //
// errorFlag = 0;
// }
//
// If something unexpected caused the interrupt, this would handle it.
//
else
{
//
// Spurious interrupt handling can go here.
//
}
// Clear the global interrupt flag for the CAN interrupt line
CAN_clearGlobalInterruptStatus(CANA_BASE, CAN_GLOBAL_INT_CANINT0);
PieCtrlRegs.PIEACK.all = PIEACK_GROUP9;
}
