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https://opencores.org/ocsvn/openrisc_2011-10-31/openrisc_2011-10-31/trunk
Subversion Repositories openrisc_2011-10-31
[/] [openrisc/] [trunk/] [rtos/] [freertos-6.1.1/] [Demo/] [HCS12_GCC_banked/] [serial.c] - Rev 620
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/* serial.c for using FreeRTOS Copyright (C) 2005 Robotronics Inc. */ /* BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER for port 1. GCC demo modifications by Jeff Smith, Robotronics Inc. 2005 */ #include "cpu.h" #include <sys/sio.h> /* Scheduler include files. */ #include "FreeRTOS.h" #include "queue.h" #include "task.h" /* Demo application include files. */ #include "sci.h" #include "serial.h" /* The queues used to communicate between the task code and the interrupt service routines. */ static xQueueHandle xRxedChars; static xQueueHandle xCharsForTx; /* Interrupt identification bits. */ #define serOVERRUN_INTERRUPT ( '\x08' ) #define serRX_INTERRUPT ( 0x20 ) #define serTX_INTERRUPT ( 0x80 ) /*-----------------------------------------------------------*/ /* * Initialise port for interrupt driven communications. */ xComPortHandle xSerialPortInitMinimal( unsigned long ulWantedBaud, unsigned portBASE_TYPE uxQueueLength ) { /* Hardware setup is performed by the Processor Expert generated code. This function just creates the queues used to communicate between the interrupt code and the task code - then sets the required baud rate. */ xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed char ) ); xCharsForTx = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed char ) ); SCI_SetBaudRateMode( ( char ) ulWantedBaud ); return NULL; } /*-----------------------------------------------------------*/ signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed char *pcRxedChar, portTickType xBlockTime ) { /* Get the next character from the buffer queue. Return false if no characters are available, or arrive before xBlockTime expires. */ if( xQueueReceive( xRxedChars, pcRxedChar, xBlockTime ) ) { return pdTRUE; } else { return pdFALSE; } } /*-----------------------------------------------------------*/ signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed char cOutChar, portTickType xBlockTime ) { /* Place the character in the queue of characters to be transmitted. */ if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) != pdPASS ) { return pdFAIL; } /* Turn on the Tx interrupt so the ISR will remove the character from the queue and send it. This does not need to be in a critical section as if the interrupt has already removed the character the next interrupt will simply turn off the Tx interrupt again. */ SCICR2 |= 0x80; // TIE return pdPASS; } /*-----------------------------------------------------------*/ void vSerialClose( xComPortHandle xPort ) { /* Not supported. */ //( void ) xPort; } /*-----------------------------------------------------------*/ /* * Interrupt service routine for the serial port. Must be in non-banked * memory. */ void ATTR_INT ATTR_NEAR vCOM_ISR( void ); void vCOM_ISR( void ) { volatile unsigned char ucByte, ucStatus; portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE; /* What caused the interrupt? */ ucStatus = SCISR1; if( ucStatus & serOVERRUN_INTERRUPT ) { /* The interrupt was caused by an overrun. Clear the error by reading the data register. */ ucByte = SCIDRL; } else if( ucStatus & serRX_INTERRUPT ) { /* The interrupt was caused by a character being received. Read the received byte. */ ucByte = SCIDRL; /* Post the character onto the queue of received characters - noting whether or not this wakes a task. */ xQueueSendFromISR( xRxedChars, ( void * ) &ucByte, &xHigherPriorityTaskWoken ); } if( ( ucStatus & serTX_INTERRUPT ) && ( SCICR2 & 0x80 ) ) { /* The interrupt was caused by a character being transmitted. */ if( xQueueReceiveFromISR( xCharsForTx, ( void * ) &ucByte, &xHigherPriorityTaskWoken ) == pdTRUE ) { /* Clear the SCRF bit. */ SCIDRL = ucByte; } else { /* Disable transmit interrupt */ SCICR2 &= ~0x80; // TIE } } if( xHigherPriorityTaskWoken ) { portYIELD(); } }
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