我的CAN发送程序如下：

UINT8 u8CAN_SendFrame(UINT32 u32ID, UINT8 u8Prio, UINT8 u8Length, UINT8 *u8TxData)
{
/* Transmission buffer */
UINT8 u8TxBuffer = {0};

/* Index to data within the transmission buffer */
UINT8 u8Index;

if (!CAN0TFLG) /* Retrun if Transmit Buffer is full */
return ERR_BUFFER_FULL;

CAN0TBSEL = CAN0TFLG; /* Select lowest empty buffer */
u8TxBuffer = CAN0TBSEL; /* Backup selected buffer */


*((UINT32 *) ((UINT32)(&CAN0TXIDR0)))= u32ID; /* Load Id to IDR Registers */

/* Load data to Data Segment Registers */
for (u8Index=0;u8Index<u8Length;u8Index++) {
*(&CAN0TXDSR0 + u8Index) = u8TxData[u8Index];
}

CAN0TXDLR = u8Length; /* Set Data Length Code */
CAN0TXTBPR = u8Prio; /* Set Priority */

CAN0TFLG = u8TxBuffer; /* Start transmission */

while ( (CAN0TFLG & u8TxBuffer) != u8TxBuffer);/* Wait for Transmission completion */

return NO_ERR;
}
问题：1。当发送不成功时，也就是CAN0TFLG相应的位没有被置位，程序就会在while ( (CAN0TFLG & u8TxBuffer) != u8TxBuffer);

处进入死循环，那么此时CAN控制器是会将报文重新发送呢，还是一直在等待对方的ACK回应呢？

2。还有，我检查了控制器中的CAN同步寄存器位，发现它为未同步状态，可之前初始化时是同步成功的啊，为何会出错呢？

谢谢指点，急求解答

没有人能帮帮忙吗 ,自己顶一下