Posted on June 06, 2006 at 10:27Hi, I am having some trouble with UARTs. It happens not very often, but it happens.
I am using the 4 UARTs. In the middle of a data transfer through UART3, (half duplex, which sends some data, waits ACK, sends more data, and so on..) it suddenly hangs my application. By making some debug with JTAG, I noticed that UART0 enters in the interrupt routine countinously (as if some interrupt bit is always set), but I dont know why. These are the values of some registers I got from UART0:
CR: 0x05A9
IER: 0x0140
SR: 0x0006
My communication module (the one who handles the 4 UARTs) is using interrupts and FIFOs. It just makes some buffering of data.
This code is the ISR:
Code:
static void CommISRHandler(commbuffer_t *pBuffer, UART_TypeDef *UARTx)
{
uint16_t FlagStatus;
uint16_t nError;
FlagStatus = UART_FlagStatus(UARTx) & UARTx->IER;
/* Check any TX Interrupt */
if (FlagStatus & (UART_TxEmpty | UART_TxHalfEmpty)) {
do {
/* Is there any data to send? */
if (0 == pBuffer->BufferTxCtr) {
/* No, so turn off TX interrupts */
UART_ItConfig(UARTx, UART_TxEmpty | UART_TxHalfEmpty, DISABLE);
break;
}
/* Put new data */
UARTx->TxBUFR = CommGetCharISR(pBuffer, &nError);
/* Repeat until UART is full */
} while (UART_FlagStatus(UARTx) & UART_TxFull);
}
/* Check any RX Interrupt */
if (FlagStatus & (UART_RxHalfFull | UART_TimeOutNotEmpty)) {
do {
/* Add Data to Buffer */
CommPutCharISR(pBuffer, UARTx->RxBUFR);
/* UART_RxBufFull in fact means UART_RxBufNotEmpty */
/* So, repeat until no data is present */
} while (UART_FlagStatus(UARTx) & UART_RxBufFull);
}
}
The ISR has two parameters:
commbuffer_t *pBuffer -> points to the corresponding buffer structure
UART_TypeDef *UARTx -> points to corresponding UART
My 4 UART Interrupt handlers only call this routine, for instance:
Code:
void Comm0ISR(void)
{
CommISRHandler(Buffers[0], UART0);
return;
}
Any suggestion?
Regards,
