help with a delay function

[t.man]

i want to make a delay of, say 100uS using 1 Mhz oscilator, so i see a function like this can do the work,

void delay(unsigned char i)
{
	unsigned char n;
	unsigned int j;
	for (n=1; n<i; n++)
	{
		for (j=1; j<1535; j++);
	}

...but my problem is how to figure out how this function really do the delay of, say 1 seconds, etc. when it is called.

anyone to come to my rescue?

thanks,

 

[ericgibbs]

i want to make a delay of, say 100uS using 1 Mhz oscilator, so i see a function like this can do the work,

void delay(unsigned char i)
{
	unsigned char n;
	unsigned int j;
	for (n=1; n<i; n++)
	{
		for (j=1; j<1535; j++);
	}

...but my problem is how to figure out how this function really do the delay of, say 1 seconds, etc. when it is called.

anyone to come to my rescue?

thanks,

hi,
If you are using a PIC with a 1MHz crystal.? the internal cycle execution time will be 1MHz/4 ie: == 4uSec/execution cycle.

I dont program in 'C', but the idea is the same in assembler.
You count the total program execution cycles [bytes] around the loop, this gives the total delay period.

Do this help.?

 

[Pommie]

You can run it in the simulator and use the stop watch to time it. Alternatively, you could include the delay routines supplied by Microchip.

Mike.