M0_CAN中断的问题

只看该作者 · 2011-12-3 09:00

void CAN_IRQHandler(void)
{
  uint32_t canstat = canstat;
  uint32_t can_int, msg_no;
while ( (can_int = LPC_CAN->INT) != 0 )
  {
if ( can_int & CAN_STATUS_INTERRUPT )
{
canstat = LPC_CAN->STAT;
#if CAN_DEBUG
CANStatusLog[CANStatusLogCount++] = canstat;
#endif
if ( canstat & STAT_EWARN )
{
  EWarnCnt++;
  return;
}
if ( canstat & STAT_BOFF )
{
  BOffCnt++;
  return;
}
}
else
{
   if ( (canstat & STAT_LEC) == 0 )  /* NO ERROR */
{
  /* deal with RX only for now. */
  msg_no = can_int & 0x7FFF;
  if ( (msg_no >= 0x01) && (msg_no <= 0x20) )
  {
LPC_CAN->STAT &= ~STAT_RXOK;
CAN_MessageProcess( msg_no-1 );
CANRxDone[msg_no-1] = TRUE;
  }
}
}
  }
  return;
}
#endif
问一下CAN收到数据进入这个中断时LPC_CAN->INT为状态中断，LPC_CAN->STAT为RXOK。那这个程序不是一接收到CAN数据就就马上产生状态中断么，怎么会进入ELSE里的报文中断里去呢？