how to know in software when PIC PWM cycle starts/ends?

[coffeeCupPepsi]

PWM sync

Hi!
I'm using a 16f88.
How can I sync to the PWM? i.e. can I know in software when the PWM cycle starts/ends?
I need to 'switch' the path of the PWM on alternate pulses, I'll use another digital output to control the path of the PWM via NAND gates.
I know there are other PICs with two or more PWM output pins, but I want to use my 16f88, and besides i need the pulses to alternate, so even if i had two PWMs i still need to know in software the start/end of cycle in order to sync them...
it could be as easy as just cheking a flag in some register, but i can't find it in the data sheet.
could i set an interrupt when tmr2 reaches 0 ? would this affect the opperation of PWM?

Thanks in advance this is my first post.

 

[wp100]

Hi,

Interesting point -- is Timer2 flag available when allocated to PWM ?

Well have just done this test on a 18F4520 and it seems to say it is.

Register PIR1, Bit1 TMR2IF is changed from 0 to 1 by the program - its the same in the 16F88.

You may be able to test that flag in your code loop although it might be better to use the interrupt system PIE1,TMR2IE etc.

 

[coffeeCupPepsi]

thanks mate for the quick reply and for actualy testing it out!