First version under SVN is V4.0.1

Demo/PIC18_WizC/serial/serial.c

@@ -0,0 +1,177 @@
+/*
+	FreeRTOS V4.0.1 - Copyright (C) 2003-2006 Richard Barry.
+
+	This file is part of the FreeRTOS distribution.
+
+	FreeRTOS is free software; you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation; either version 2 of the License, or
+	(at your option) any later version.
+
+	FreeRTOS is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with FreeRTOS; if not, write to the Free Software
+	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+	A special exception to the GPL can be applied should you wish to distribute
+	a combined work that includes FreeRTOS, without being obliged to provide
+	the source code for any proprietary components.  See the licensing section 
+	of http://www.FreeRTOS.org for full details of how and when the exception
+	can be applied.
+
+	***************************************************************************
+	See http://www.FreeRTOS.org for documentation, latest information, license 
+	and contact details.  Please ensure to read the configuration and relevant 
+	port sections of the online documentation.
+	***************************************************************************
+*/
+
+/*
+Changes from V3.0.0
+	+ ISRcode removed. Is now pulled inline to reduce stack-usage.
+
+Changes from V3.0.1
+*/
+
+/* BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER. */
+
+/* Scheduler header files. */
+#include "FreeRTOS.h"
+#include "task.h"
+#include "queue.h"
+
+#include "serial.h"
+
+/* Hardware pin definitions. */
+#define serTX_PIN				bTRC6
+#define serRX_PIN				bTRC7
+
+/* Bit/register definitions. */
+#define serINPUT				( 1 )
+#define serOUTPUT				( 0 )
+#define serINTERRUPT_ENABLED 	( 1 )
+
+/* All ISR's use the PIC18 low priority interrupt. */
+#define	serLOW_PRIORITY			( 0 )
+
+/*-----------------------------------------------------------*/
+
+/* Queues to interface between comms API and interrupt routines. */
+xQueueHandle xRxedChars; 
+xQueueHandle xCharsForTx;
+
+/*-----------------------------------------------------------*/
+
+xComPortHandle xSerialPortInitMinimal( unsigned portLONG ulWantedBaud, unsigned portCHAR ucQueueLength )
+{
+	unsigned portSHORT usSPBRG;
+	
+	/* Create the queues used by the ISR's to interface to tasks. */
+	xRxedChars = xQueueCreate( ucQueueLength, ( unsigned portBASE_TYPE ) sizeof( portCHAR ) );
+	xCharsForTx = xQueueCreate( ucQueueLength, ( unsigned portBASE_TYPE ) sizeof( portCHAR ) );
+
+	portENTER_CRITICAL();
+
+	/* Setup the IO pins to enable the USART IO. */
+	serTX_PIN	= serINPUT;		// YES really! See datasheet
+	serRX_PIN	= serINPUT;
+
+	/* Set the TX config register. */
+	TXSTA = 0b00100000;
+		//	  ||||||||--bit0: TX9D	= n/a
+		//	  |||||||---bit1: TRMT	= ReadOnly
+		//	  ||||||----bit2: BRGH	= High speed
+		//	  |||||-----bit3: SENDB = n/a
+		//	  ||||------bit4: SYNC	= Asynchronous mode
+		//	  |||-------bit5: TXEN	= Transmit enable
+		//	  ||--------bit6: TX9	= 8-bit transmission
+		//	  |---------bit7: CSRC	= n/a
+
+	/* Set the Receive config register. */
+	RCSTA = 0b10010000;
+		//	  ||||||||--bit0: RX9D	= ReadOnly
+		//	  |||||||---bit1: OERR	= ReadOnly
+		//	  ||||||----bit2: FERR	= ReadOnly
+		//	  |||||-----bit3: ADDEN	= n/a
+		//	  ||||------bit4: CREN	= Enable receiver
+		//	  |||-------bit5: SREN	= n/a
+		//	  ||--------bit6: RX9	= 8-bit reception
+		//	  |---------bit7: SPEN	= Serial port enabled
+
+	/* Calculate the baud rate generator value.
+	   We use low-speed (BRGH=0), the formula is
+	   SPBRG = ( ( FOSC / Desired Baud Rate ) / 64 ) - 1 */
+	usSPBRG = ( ( APROCFREQ / ulWantedBaud ) / 64 ) - 1;
+	if( usSPBRG > 255 )
+	{
+		SPBRG = 255;
+	}
+	else
+	{
+		SPBRG = usSPBRG;
+	}
+
+	/* Set the serial interrupts to use the same priority as the tick. */
+	bTXIP = serLOW_PRIORITY;
+	bRCIP = serLOW_PRIORITY;
+
+	/* Enable the Rx interrupt now, the Tx interrupt will get enabled when
+	we have data to send. */
+	bRCIE = serINTERRUPT_ENABLED;
+	
+	portEXIT_CRITICAL();
+
+	/* Unlike other ports, this serial code does not allow for more than one
+	com port.  We therefore don't return a pointer to a port structure and 
+	can	instead just return NULL. */
+	return NULL;
+}
+/*-----------------------------------------------------------*/
+
+xComPortHandle xSerialPortInit( eCOMPort ePort, eBaud eWantedBaud, eParity eWantedParity, eDataBits eWantedDataBits, eStopBits eWantedStopBits, unsigned portCHAR ucBufferLength )
+{
+	/* This is not implemented in this port.
+	Use xSerialPortInitMinimal() instead. */
+	return NULL;
+}
+/*-----------------------------------------------------------*/
+
+portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, portCHAR *pcRxedChar, portTickType xBlockTime )
+{
+	/* Get the next character from the buffer.  Return false if no characters
+	are available, or arrive before xBlockTime expires. */
+	if( xQueueReceive( xRxedChars, pcRxedChar, xBlockTime ) )
+	{
+		return ( portCHAR ) pdTRUE;
+	}
+
+	return ( portCHAR ) pdFALSE;
+}
+/*-----------------------------------------------------------*/
+
+portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, portCHAR cOutChar, portTickType xBlockTime )
+{
+	/* Return false if after the block time there is no room on the Tx queue. */
+	if( xQueueSend( xCharsForTx, ( const void * ) &cOutChar, xBlockTime ) != ( portCHAR ) pdPASS )
+	{
+		return pdFAIL;
+	}
+
+	/* Turn interrupt on - ensure the compiler only generates a single 
+	instruction for this. */
+	bTXIE = serINTERRUPT_ENABLED;
+
+	return pdPASS;
+}
+/*-----------------------------------------------------------*/
+
+void vSerialClose( xComPortHandle xPort )
+{
+	/* Not implemented for this port.
+	To implement, turn off the interrupts and delete the memory
+	allocated to the queues. */
+}