I've got some code here which I suspect might be the cause of a watchdog reset occurring on our board, but so far haven't been able to identify the root cause. Is there a condition here that's not getting handled resulting in a stuck interrupt (see code below)? I'm also wondering if there are any recommended methods for tracking this problem down using DSP/BIOS v5.41?
Any help or pointers would be greatly appreciated.
void HWI_uartIRQ(void)
{
Uint16 value;
Uint16 event;
/* read the interrupt identification register */
UART_FSET(URLCR, DLAB, 0);
value = UART_RGET(URIIR);
while ((value & 0x01) == 0)
{
/* interrupt pending */
event = (value & 0x0e) >> 1;
switch (event)
{
case UART_URIIR_IID_RCLINESTATUS:
// read the line status register and record statistics
value = UART_RGET(URLSR);
uartStats.lsr++;
if (value & 0x0002)
{
// count the overrun error, cleared by reading LSR
uartStats.oe++;
}
if (value & 0x0004)
{
// discard character with parity error
UART_RGET(URRBR);
uartStats.pe++;
}
if (value & 0x0008)
{
// discard character with framing error
UART_RGET(URRBR);
uartStats.fe++;
}
if (value & 0x0010)
{
// discard character with break indicator
UART_RGET(URRBR);
uartStats.bi++;
}
if (value & 0x0080)
{
// discard character with receiver fifo error indicated
UART_RGET(URRBR);
uartStats.rfier++;
}
break;
case UART_URIIR_IID_CHARTIMEOUT:
// receiver time-out interrupt
uartStats.rxTimeout++;
// fall through
case UART_URIIR_IID_RCDATA:
// receiver data ready
while( UART_FGET(URLSR, DR) )
{
/* read data */
*pWrite++ = UART_RGET(URRBR);
uartStats.dr++;
/* wrap pointer */
if (pWrite >= rxBuffer + UART_BUFSIZE)
{
pWrite = rxBuffer;
}
}
/* notify application */
SEM_postBinary(uartRxSem);
break;
case UART_URIIR_IID_TXEMPTY:
// transmitter holding register empty
uartStats.thre++;
break;
default:
uartStats.unknown++;
break;
}
value = UART_RGET(URIIR);
}
return;
}
/*
@details Initializes the on-board UART */
Uint16 uartInit (void)
{
Uint16 tempbaud;
/* allocate resources */
if ((rxBuffer = MEM_alloc(sdram_heap, UART_BUFSIZE, 4)) == NULL)
{
LOG_0 (LOG_ERROR, "ERROR: failed to allocate rxBuffer");
return(AP_FAIL);
}
pWrite = pRead = rxBuffer;
if ((uartRxSem = SEM_create(0, NULL)) == NULL)
{
LOG_0 (LOG_ERROR, "ERROR: failed to allocate uartRxSem");
return(AP_FAIL);
}
/* initialize stats */
memset(&uartStats, 0, sizeof(UartGetStatsRsp));
/* Set BSR to disable SP2MODE */
CHIP_FSET(XBSR, SP2MODE, 0);
/* disable all UART events */
UART_FSET(URLCR, DLAB, 0);
UART_RSET(URIER, UART_NOINT);
/* reset and enable FIFO */
UART_RSET(URFCR, 0x7);
UART_RSET(URFCR, UART_FIFO_DMA0_TRIG14);
/* set DLL and DLM to values appropriate for the required baudrate */
tempbaud = (Uint16)((Uint32)UART_CLK_INPUT_100 * (Uint32)UART_BAUD_115200 >>
6);
UART_FSET(URLCR, DLAB, 1);
UART_RSET(URDLL, (tempbaud & 0xff));
UART_RSET(URDLM, (tempbaud >> 8));
UART_FSET(URLCR, DLAB, 0);
/* setup word size, stop bits and parity */
UART_RSET(URLCR, UART_WORD8 | UART_STOP1 | UART_DISABLE_PARITY);
/* disable loopback */
UART_RSET(URMCR, UART_NO_LOOPBACK);
/* enable interrupts */
IRQ_enable(IRQ_EVT_UART);
UART_RSET(URIER, 0x5);
/* take UART out of reset */
UART_FSET(URPECR, URST, 1);
return (AP_SUCCESS);
}
