Re: Pic 12f675 c code - ccs compiler

[Kandeepan]

Re: Pic 12f675 c code - ccs compiler

Anybody there to explain me as I'm very new to PIC C programming. What does it mean by " set_timer0(42);"
Looking forward to hear from you soon.

Regards

Kandeepan

 

[assasinsareus]

Re: Pic 12f675 c code - ccs compiler

Hello,

Im not a common user of the CCS compiler but is it setting the timer count register to 42? Maybe it is also enabling the timer with that value as a fixed rollover value.

eg timers count from 0 to 255 (8-bit) or 0 to 65536 (16-bit). When they rollover from their max count to 0 the timer generates an interrupt. If you preload a value in the count register then the timer will reach it's rollover faster as it has less to count. This timer preloading is useful for accurate timing etc.

 

[tahir4awan]

Re: Pic 12f675 c code - ccs compiler

yes it is the starting number of timer. Timer0 is an 8bit timer i.e 2^8 = 256 so it counts from 0 to 255.For any reason if you don't want to start timer from 0 you can assign any value (0 - 255). In you example the timer will start from 42 to 255 and set the interrupt flag. The timer will not stop counting after interrupt it will keep on counting from 42 to 255. The timer value is adjusted according to the time requirements.

 

[necati]

Re: Pic 12f675 c code - ccs compiler

///////////////////////////////////////////////
#include <12F675.h>
#use delay(clock=4000000)
#fuses INTRC_IO,NOWDT,NOCPD,NOPROTECT,nomclr
#use rs232(baud=9600,xmit=PIN_A1)
int16 seco=0;

#int_timer0

void ms_100(){

set_timer1(42);

seco++;
}
/////////////////////////////////////////////
void main( void ){
SET_TRIS_A (0b00000101);
setup_adc_ports( NO_ANALOGS );
//SETUP_TIMER_0(t0_internal|T0_DIV_256);//int
SETUP_TIMER_0(T0_EXT_L_TO_H|T0_DIV_1); //ext
enable_interrupts(int_timer0);
enable_interrupts(global);
seco=0;
/////////////////////////////////////////////
while(true){
printf( "\n\r seco:%6ld",seco );
delay_ms(100);
}
}

 

[tahir4awan]

Re: Pic 12f675 c code - ccs compiler

CCS compiler programing looks similar to BASIC programing.