/* | |
FreeRTOS.org V5.1.2 - Copyright (C) 2003-2009 Richard Barry. | |
This file is part of the FreeRTOS.org distribution. | |
FreeRTOS.org 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. | |
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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.org; if not, write to the Free Software | |
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A special exception to the GPL can be applied should you wish to distribute | |
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the source code for any proprietary components. See the licensing section | |
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*************************************************************************** | |
*************************************************************************** | |
* * | |
* Get the FreeRTOS eBook! See http://www.FreeRTOS.org/Documentation * | |
* * | |
* This is a concise, step by step, 'hands on' guide that describes both * | |
* general multitasking concepts and FreeRTOS specifics. It presents and * | |
* explains numerous examples that are written using the FreeRTOS API. * | |
* Full source code for all the examples is provided in an accompanying * | |
* .zip file. * | |
* * | |
*************************************************************************** | |
*************************************************************************** | |
Please ensure to read the configuration and relevant port sections of the | |
online documentation. | |
http://www.FreeRTOS.org - Documentation, latest information, license and | |
contact details. | |
http://www.SafeRTOS.com - A version that is certified for use in safety | |
critical systems. | |
http://www.OpenRTOS.com - Commercial support, development, porting, | |
licensing and training services. | |
*/ | |
/* | |
* The comms test Rx and Tx task and co-routine. See the comments at the top | |
* of main.c for full information. | |
*/ | |
/* Scheduler include files. */ | |
#include "FreeRTOS.h" | |
#include "task.h" | |
#include "queue.h" | |
#include "croutine.h" | |
/* Demo application include files. */ | |
#include "partest.h" | |
/* Library include files. */ | |
#include "DriverLib.h" | |
/* The LED's toggled by the various tasks. */ | |
#define commsFAIL_LED ( 7 ) | |
#define commsRX_LED ( 6 ) | |
#define commsTX_LED ( 5 ) | |
/* The length of the queue used to pass received characters to the Comms Rx | |
task. */ | |
#define commsRX_QUEUE_LEN ( 5 ) | |
/* The baud rate used by the UART comms tasks/co-routine. */ | |
#define commsBAUD_RATE ( 57600 ) | |
/* FIFO setting for the UART. The FIFO is not used to create a better test. */ | |
#define commsFIFO_SET ( 0x10 ) | |
/* The string that is transmitted on the UART contains sequentially the | |
characters from commsFIRST_TX_CHAR to commsLAST_TX_CHAR. */ | |
#define commsFIRST_TX_CHAR '0' | |
#define commsLAST_TX_CHAR 'z' | |
/* Just used to walk through the program memory in order that some random data | |
can be generated. */ | |
#define commsTOTAL_PROGRAM_MEMORY ( ( unsigned portLONG * ) ( 8 * 1024 ) ) | |
#define commsFIRST_PROGRAM_BYTES ( ( unsigned portLONG * ) 4 ) | |
/* The time between transmissions of the string on UART 0. This is pseudo | |
random in order to generate a bit or randomness to when the interrupts occur.*/ | |
#define commsMIN_TX_DELAY ( 40 / portTICK_RATE_MS ) | |
#define commsMAX_TX_DELAY ( ( portTickType ) 0x7f ) | |
#define commsOFFSET_TIME ( ( portTickType ) 3 ) | |
/* The time the Comms Rx task should wait to receive a character. This should | |
be slightly longer than the time between transmissions. If we do not receive | |
a character after this time then there must be an error in the transmission or | |
the timing of the transmission. */ | |
#define commsRX_DELAY ( commsMAX_TX_DELAY + 20 ) | |
static unsigned portBASE_TYPE uxCommsErrorStatus = pdPASS; | |
/* The queue used to pass characters out of the ISR. */ | |
static xQueueHandle xCommsQueue; | |
/* The next character to transmit. */ | |
static portCHAR cNextChar; | |
/*-----------------------------------------------------------*/ | |
void vSerialInit( void ) | |
{ | |
/* Create the queue used to communicate between the UART ISR and the Comms | |
Rx task. */ | |
xCommsQueue = xQueueCreate( commsRX_QUEUE_LEN, sizeof( portCHAR ) ); | |
/* Enable the UART. GPIOA has already been initialised. */ | |
SysCtlPeripheralEnable(SYSCTL_PERIPH_UART0); | |
/* Set GPIO A0 and A1 as peripheral function. They are used to output the | |
UART signals. */ | |
GPIODirModeSet( GPIO_PORTA_BASE, GPIO_PIN_0 | GPIO_PIN_1, GPIO_DIR_MODE_HW ); | |
/* Configure the UART for 8-N-1 operation. */ | |
UARTConfigSetExpClk( UART0_BASE, SysCtlClockGet(), commsBAUD_RATE, UART_CONFIG_WLEN_8 | UART_CONFIG_PAR_NONE | UART_CONFIG_STOP_ONE ); | |
/* We dont want to use the fifo. This is for test purposes to generate | |
as many interrupts as possible. */ | |
HWREG( UART0_BASE + UART_O_LCR_H ) &= ~commsFIFO_SET; | |
/* Enable both Rx and Tx interrupts. */ | |
HWREG( UART0_BASE + UART_O_IM ) |= ( UART_INT_TX | UART_INT_RX ); | |
IntPrioritySet( INT_UART0, configKERNEL_INTERRUPT_PRIORITY ); | |
IntEnable( INT_UART0 ); | |
} | |
/*-----------------------------------------------------------*/ | |
void vSerialTxCoRoutine( xCoRoutineHandle xHandle, unsigned portBASE_TYPE uxIndex ) | |
{ | |
portTickType xDelayPeriod; | |
static unsigned portLONG *pulRandomBytes = commsFIRST_PROGRAM_BYTES; | |
/* Co-routine MUST start with a call to crSTART. */ | |
crSTART( xHandle ); | |
for(;;) | |
{ | |
/* Was the previously transmitted string received correctly? */ | |
if( uxCommsErrorStatus != pdPASS ) | |
{ | |
/* An error was encountered so set the error LED. */ | |
vParTestSetLED( commsFAIL_LED, pdTRUE ); | |
} | |
/* The next character to Tx is the first in the string. */ | |
cNextChar = commsFIRST_TX_CHAR; | |
UARTIntDisable( UART0_BASE, UART_INT_TX ); | |
{ | |
/* Send the first character. */ | |
if( !( HWREG( UART0_BASE + UART_O_FR ) & UART_FR_TXFF ) ) | |
{ | |
HWREG( UART0_BASE + UART_O_DR ) = cNextChar; | |
} | |
/* Move the variable to the char to Tx on so the ISR transmits | |
the next character in the string once this one has completed. */ | |
cNextChar++; | |
} | |
UARTIntEnable(UART0_BASE, UART_INT_TX); | |
/* Toggle the LED to show a new string is being transmitted. */ | |
vParTestToggleLED( commsTX_LED ); | |
/* Delay before we start the string off again. A pseudo-random delay | |
is used as this will provide a better test. */ | |
xDelayPeriod = xTaskGetTickCount() + ( *pulRandomBytes ); | |
pulRandomBytes++; | |
if( pulRandomBytes > commsTOTAL_PROGRAM_MEMORY ) | |
{ | |
pulRandomBytes = commsFIRST_PROGRAM_BYTES; | |
} | |
/* Make sure we don't wait too long... */ | |
xDelayPeriod &= commsMAX_TX_DELAY; | |
/* ...but we do want to wait. */ | |
if( xDelayPeriod < commsMIN_TX_DELAY ) | |
{ | |
xDelayPeriod = commsMIN_TX_DELAY; | |
} | |
/* Block for the random(ish) time. */ | |
crDELAY( xHandle, xDelayPeriod ); | |
} | |
/* Co-routine MUST end with a call to crEND. */ | |
crEND(); | |
} | |
/*-----------------------------------------------------------*/ | |
void vUART_ISR( void ) | |
{ | |
unsigned portLONG ulStatus; | |
portCHAR cRxedChar; | |
portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE; | |
/* What caused the interrupt. */ | |
ulStatus = UARTIntStatus( UART0_BASE, pdTRUE ); | |
/* Clear the interrupt. */ | |
UARTIntClear( UART0_BASE, ulStatus ); | |
/* Was an Rx interrpt pending? */ | |
if( ulStatus & UART_INT_RX ) | |
{ | |
if( ( HWREG(UART0_BASE + UART_O_FR ) & UART_FR_RXFF ) ) | |
{ | |
/* Get the char from the buffer and post it onto the queue of | |
Rxed chars. Posting the character should wake the task that is | |
blocked on the queue waiting for characters. */ | |
cRxedChar = ( portCHAR ) HWREG( UART0_BASE + UART_O_DR ); | |
xQueueSendFromISR( xCommsQueue, &cRxedChar, &xHigherPriorityTaskWoken ); | |
} | |
} | |
/* Was a Tx interrupt pending? */ | |
if( ulStatus & UART_INT_TX ) | |
{ | |
/* Send the next character in the string. We are not using the FIFO. */ | |
if( cNextChar <= commsLAST_TX_CHAR ) | |
{ | |
if( !( HWREG( UART0_BASE + UART_O_FR ) & UART_FR_TXFF ) ) | |
{ | |
HWREG( UART0_BASE + UART_O_DR ) = cNextChar; | |
} | |
cNextChar++; | |
} | |
} | |
/* If a task was woken by the character being received then we force | |
a context switch to occur in case the task is of higher priority than | |
the currently executing task (i.e. the task that this interrupt | |
interrupted.) */ | |
portEND_SWITCHING_ISR( xHigherPriorityTaskWoken ); | |
} | |
/*-----------------------------------------------------------*/ | |
void vCommsRxTask( void * pvParameters ) | |
{ | |
static portCHAR cRxedChar, cExpectedChar; | |
/* Set the char we expect to receive to the start of the string. */ | |
cExpectedChar = commsFIRST_TX_CHAR; | |
for( ;; ) | |
{ | |
/* Wait for a character to be received. */ | |
xQueueReceive( xCommsQueue, ( void * ) &cRxedChar, commsRX_DELAY ); | |
/* Was the character recived (if any) the expected character. */ | |
if( cRxedChar != cExpectedChar ) | |
{ | |
/* Got an unexpected character. This can sometimes occur when | |
reseting the system using the debugger leaving characters already | |
in the UART regsters. */ | |
uxCommsErrorStatus = pdFAIL; | |
/* Resync by waiting for the end of the current string. */ | |
while( cRxedChar != commsLAST_TX_CHAR ) | |
{ | |
while( !xQueueReceive( xCommsQueue, ( void * ) &cRxedChar, portMAX_DELAY ) ); | |
} | |
/* The next expected character is the start of the string again. */ | |
cExpectedChar = commsFIRST_TX_CHAR; | |
} | |
else | |
{ | |
if( cExpectedChar == commsLAST_TX_CHAR ) | |
{ | |
/* We have reached the end of the string - we now expect to | |
receive the first character in the string again. The LED is | |
toggled to indicate that the entire string was received without | |
error. */ | |
vParTestToggleLED( commsRX_LED ); | |
cExpectedChar = commsFIRST_TX_CHAR; | |
} | |
else | |
{ | |
/* We got the expected character, we now expect to receive the | |
next character in the string. */ | |
cExpectedChar++; | |
} | |
} | |
} | |
} | |
/*-----------------------------------------------------------*/ | |
unsigned portBASE_TYPE uxGetCommsStatus( void ) | |
{ | |
return uxCommsErrorStatus; | |
} |