Help Porting Atmega644->FreeRtos

Kernel
1

freetones wrote on Wednesday, 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 <stdlib.h>
#include <avr/interrupt.h>

#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

2

bfi3103 wrote on Wednesday, 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<<COM1A1 )
#define portPRESCALE_1024						( (1<<CS12) | (1<<CS10) )
#define portPRESCALE_256						( 1<<CS12 )
#define portPRESCALE_64							( (1<<CS11) | (1<<CS10) )
#define portCLOCK_PRESCALER						( 64 )
#define portCOMPARE_MATCH_A_INTERRUPT_ENABLE	( 1<<OCIE1A )
#define TIMSK									TIMSK1
#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<<PD5);
    TCCR1A = (0<<COM1A1) | (0<<COM1A0)  //  normal operation (or toggle OC1A = PD5 on compare match)
           | (0<<COM1B1) | (0<<COM1B0)  //  normal operation
           | (0<<WGM11)  | (0<<WGM10);  //  CTC (together with WGM12 and WGM13)
                                        //  TOP is OCR1A
	/* Setup clock source and compare match behaviour. */
	// ucLowByte = portCLEAR_COUNTER_ON_MATCH | portPRESCALE_64;
	// TCCR1B = ucLowByte;
    TCCR1B = (0<<ICNC1)  | (0<<ICES1)   // Noise Canceler: Off
           | (0<<WGM13)  | (1<<WGM12)
           | (0<<CS12)   | (1<<CS11) | (1<<CS10);  // no prescaler, source = sys_clk
    TCCR1C = (0<<FOC1A)  | (0<<FOC1B);   //  reserved in PWM, set to zero
	/* 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