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Help Porting Atmega644->FreeRtos

Posted by Slaxtrack on April 27, 2011
I have a configuration problem, I'm trying to adapt the atmega323 port -> to Atmega644 but
when I try to run 2 tasks does not work.


My code

#include
#include

#include "FreeRTOS.h"
#include "task.h"

/*-----------------------------------------------------------
* Implementation of functions defined in portable.h for the AVR port.
*----------------------------------------------------------*/

/* Start tasks with interrupts enables. */
#define portFLAGS_INT_ENABLED( ( portSTACK_TYPE ) 0x01 ) /// ....> ????? ist a register?? or interrupt mask register??

/* Hardware constants for timer 1. */
#define portCLEAR_COUNTER_ON_MATCH( ( unsigned char ) 0x08 )
#define portPRESCALE_64( ( unsigned char ) 0x03 )
#define portCLOCK_PRESCALER( ( unsigned long ) 64 )
#define portCOMPARE_MATCH_A_INTERRUPT_ENABLE ( ( unsigned char ) 0x02 ) //ForCOMPARE_MATCH_A_INTERRUPT_ENABLE ATM644



I need your help.

Thanks Guys

RE: Help Porting Atmega644->FreeRtos

Posted by Bernd Fink on April 27, 2011
I used the following code when using a ATmega1284P and a ATmega1281:

/* Start tasks with interrupts enables. */
#define portFLAGS_INT_ENABLED( ( portSTACK_TYPE ) 0x80 )

/* Hardware constants for timer 1. */
#if !(__AVR_ATmega1284P__ || __AVR_ATmega1281__)
#define portCLEAR_COUNTER_ON_MATCH( ( unsigned char ) 0x08 )
#define portPRESCALE_64( ( unsigned char ) 0x03 )
#define portCLOCK_PRESCALER( ( unsigned long ) 64 )
#define portCOMPARE_MATCH_A_INTERRUPT_ENABLE( ( unsigned char ) 0x10 )
#else
#define portCLEAR_COUNTER_ON_MATCH( 1<#define portPRESCALE_1024( (1<#define portPRESCALE_256( 1<#define portPRESCALE_64( (1<#define portCLOCK_PRESCALER( 64 )
#define portCOMPARE_MATCH_A_INTERRUPT_ENABLE( 1<#define TIMSKTIMSK1
#endif



I also change the code for prvSetupTimerInterrupt()

static void prvSetupTimerInterrupt( void )
{
unsigned long ulCompareMatch;
unsigned char ucHighByte, ucLowByte;


/* Using 16bit timer 1 to generate the tick. Correct fuses must be
selected for the configCPU_CLOCK_HZ clock. */

ulCompareMatch = configCPU_CLOCK_HZ / configTICK_RATE_HZ;

/* We only have 16 bits so have to scale to get our required tick rate. */
ulCompareMatch /= portCLOCK_PRESCALER;

/* Adjust for correct value. */
ulCompareMatch -= ( unsigned long ) 1;

/* Setup compare match value for compare match A. Interrupts are disabled
before this is called so we need not worry here. */
ucLowByte = ( unsigned char ) ( ulCompareMatch & ( unsigned long ) 0xff );
ulCompareMatch >>= 8;
ucHighByte = ( unsigned char ) ( ulCompareMatch & ( unsigned long ) 0xff );
OCR1AH = ucHighByte;
OCR1AL = ucLowByte;

// Generate tick pulses on PD5
//DDRD |= (1< TCCR1A = (0< | (0< | (0< // TOP is OCR1A

/* Setup clock source and compare match behaviour. */
// ucLowByte = portCLEAR_COUNTER_ON_MATCH | portPRESCALE_64;
// TCCR1B = ucLowByte;
TCCR1B = (0< | (0< | (0<
TCCR1C = (0<
/* Enable the interrupt - this is okay as interrupt are currently globally
disabled. */
ucLowByte = TIMSK;
ucLowByte |= portCOMPARE_MATCH_A_INTERRUPT_ENABLE;
TIMSK = ucLowByte;
}


I tested this code with a STK500.

Hope this helps

Bernd


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