void vSerialISR( void )
{
unsigned long ulStatus;
signed char cChar;
portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
/* What caused the interrupt? */
ulStatus = BOARD_USART_BASE->US_CSR &= BOARD_USART_BASE->US_IMR;
if( ulStatus & AT91C_US_TXRDY ) {
/* The interrupt was caused by the THR becoming empty. Are there any
more characters to transmit? */
if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xHigherPriorityTaskWoken ) == pdTRUE ) {
/* A character was retrieved from the queue so can be sent to the
THR now. */
BOARD_USART_BASE->US_THR = cChar;
} else {
/* Queue empty, nothing to send so turn off the Tx interrupt. */
vInterruptOff();
}
}
if( ulStatus & AT91C_US_RXRDY ) {
/* The interrupt was caused by a character being received. Grab the
character from the RHR and place it in the queue or received
characters. */
cChar = BOARD_USART_BASE->US_RHR;
xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken );
}
/* If a task was woken by either a character being received or a character
being transmitted then we may need to switch to another task. */
portEND_SWITCHING_ISR( xHigherPriorityTaskWoken );
}
static portBASE_TYPE xComPortISR( xComPort * const pxPort )
{
unsigned short usStatusRegister;
char cChar;
portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE, xContinue = pdTRUE;
/* NOTE: THIS IS NOT AN EFFICIENT ISR AS IT IS DESIGNED SOLELY TO TEST
THE SCHEDULER FUNCTIONALITY. REAL APPLICATIONS SHOULD NOT USE THIS
FUNCTION. */
while( xContinue == pdTRUE )
{
xContinue = pdFALSE;
usStatusRegister = portINPUT_WORD( pxPort->usStatusReg );
if( usStatusRegister & serRX_READY )
{
cChar = ( char ) portINPUT_WORD( pxPort->usRxReg );
xQueueSendFromISR( pxPort->xRxedChars, &cChar, &xHigherPriorityTaskWoken );
/* Also release the semaphore - this does nothing interesting and is just a test. */
xSemaphoreGiveFromISR( pxPort->xTestSem, &xHigherPriorityTaskWoken );
/* We have performed an action this cycle - there may be other to perform. */
xContinue = pdTRUE;
}
if( pxPort->sTxInterruptOn && ( usStatusRegister & serTX_EMPTY ) )
{
if( xQueueReceiveFromISR( pxPort->xCharsForTx, &cChar, &xHigherPriorityTaskWoken ) == pdTRUE )
{
portOUTPUT_WORD( pxPort->usTxReg, ( unsigned short ) cChar );
/* We have performed an action this cycle - there may be others to perform. */
xContinue = pdTRUE;
}
else
{
/* Queue empty, nothing to send */
vInterruptOff( pxPort, serTX_HOLD_EMPTY_INT );
}
}
}
serRESET_PIC( pxPort->usIRQVector );
/* If posting to the queue woke a task that was blocked on the queue we may
want to switch to the woken task - depending on its priority relative to
the task interrupted by this ISR. */
return xHigherPriorityTaskWoken;
}
__interrupt void SIG_UART_DATA( void )
{
signed char cChar, cTaskWoken = pdFALSE;
if( xQueueReceiveFromISR( xCharsForTx, &cChar, &cTaskWoken ) == pdTRUE )
{
/* Send the next character queued for Tx. */
outb( UDR, cChar );
}
else
{
/* Queue empty, nothing to send. */
vInterruptOff();
}
}
void vSerialClose( xComPortHandle xPort )
{
unsigned char ucByte;
/* Turn off the interrupts. We may also want to delete the queues and/or
re-install the original ISR. */
portENTER_CRITICAL();
{
vInterruptOff();
ucByte = UCSRB;
ucByte &= ~serRX_INT_ENABLE;
outb( UCSRB, ucByte );
}
portEXIT_CRITICAL();
}
void vSerialClose( xComPortHandle xPort )
{
uint8_t ucByte;
/* The parameter is not used. */
( void ) xPort;
/* Turn off the interrupts. We may also want to delete the queues and/or
re-install the original ISR. */
vPortFree (serialWorkBuffer);
vQueueDelete(xRxedChars);
vQueueDelete(xCharsForTx);
portENTER_CRITICAL();
{
vInterruptOff();
ucByte = UCSR0B;
ucByte &= ~(_BV(RXCIE0));
UCSR0B = ucByte;
}
portEXIT_CRITICAL();
}
