using all the timer together in atmega 8

[selva murugesan]

hi every one,

i need to know , what are the precautions there while use the all the timers in parallel?
i want to use timer0, timer1 simultaneously. but timer0, timer1 shares same prescaler ,on which way is makes its possible?

could u give the example program for the same?


thanks in advance

 

[sreekanthr.ele]

#include "C8051F120.h"
#include<stdio.h>

#define SYSCLK 24500000

sbit LED0  	=  P1^6;
sbit LED1 = P1^7;
sbit Test =P0^3;
sfr16 T2     =  0xCC;
sfr16 RCAP3    = 0xCA;
sfr16 TMR3     = 0xCC;

xdata unsigned int delay2,delay1;
xdata unsigned long int FrequencyCount;
xdata unsigned int Timer2OverFlowCount;
xdata unsigned int Timer0Count;
unsigned int DelayinMsec = 0;

void Timer_Init();
void PORT_Init();
void Oscillator_Init();
void Interrupts_Init();
void Timer_Init();
void Reset_Sources_Init();
void Timer3_Init (int counts);

xdata unsigned int Count=0;
xdata int frequency= 0;

void main()

{
	Reset_Sources_Init();
	SFRPAGE   = CONFIG_PAGE;
	PORT_Init ();
	Oscillator_Init();
	SFRPAGE   = TIMER01_PAGE;
	Timer_Init();
	SFRPAGE = TMR3_PAGE;
    Timer3_Init (SYSCLK / 12 / 15000);
	Interrupts_Init();
	EA =1;
	while(1)
	{
	}
}

void PORT_Init()
{
    SFRPAGE   = CONFIG_PAGE;
    P0MDOUT   = 0xFF;
    XBR1      = 0x20;
    XBR2      = 0xC0;
}

void Oscillator_Init()
{
    SFRPAGE   = CONFIG_PAGE;
    OSCICN    = 0x83;
}

void Interrupts_Init()
{
    IE        = 0x82;
}

void Reset_Sources_Init()
{
    WDTCN     = 0xDE;
    WDTCN     = 0xAD;
}

void Timer_Init()
{
	char SFRPAGE_SAVE = SFRPAGE;
    SFRPAGE   = TIMER01_PAGE;
	TCON      = 0x10;
	TMOD = 0x01;
	TR0		  = 1;
	SFRPAGE   = TMR2_PAGE;
    TMR2CN    = 0x0F;
	SFRPAGE = SFRPAGE_SAVE;
}

void Timer3_Init (int counts)
{
   TMR3CN = 0x00;
   RCAP3   = -counts;
   TMR3    = 0xffff;
   EIE2   |= 0x01;
   TR3 = 1;
}


void Timer0_ISR (void) interrupt 1
{
   Test = ~Test;
   TF0 = 0;
   TL0		  = 0x06;
   TH0		  = 0xF8;
   TR0=1;
   Count++;
   if(Count > 500)
   { 
    LED0 = ~LED0; 
	Count = 0;
   }
   if(Timer0Count++ > 10000)
	{
		frequency = (Timer2OverFlowCount * 65535 + T2);
		Timer2OverFlowCount = 0;
		Timer0Count = 0;
		T2 = 0;
	}

} 

void Timer2_ISR() interrupt 5
{
	if(TF2)
	{
		TF2 = 0;
		Timer2OverFlowCount++;
	}
	if(EXF2)
	{
		EXF2 = 0;
	}
}

void Timer3_ISR (void) interrupt 14
{
   TF3 = 0;
   LED1 = ~LED1;
}