delay_us

Einly · Joined: 10 Sep 2003 Posts: 60

Dear all,

I am using 2 timer interrupt in my program (timer 0 and timer 1). Timer 0 is used to count for 1s. In this 1 second interval, timer 1 is used to count the pulses that is received. I would like to use Pin B0 interrupt which will set Pin C0 high for 7us. If I have a delay_us(7) in the pin B0 interrupt routine, will this affect the other timers operation? What will happen during the delay_us(7) line?

Thanks a lot
_________________
Einly

rwyoung · Joined: 12 Nov 2003 Posts: 563 Location: Lawrence, KS USA

Using the delay_us, delay_ms and delay_cycles functions inside interrupt service routines is generally a bad idea.

Unless you are writing your own interrupt handler there is a significant chance you will increase the latency of other interrupts because you have blocked them with a dead-head loop of NOPs inside another ISR.

ISRs should be short and to the point. Get in and get out of the ISR as quickly as you can.
_________________
Rob Young
The Screw-Up Fairy may just visit you but he has crashed on my couch for the last month!

PCM programmer · Joined: 06 Sep 2003 Posts: 21708