Checking PIC18F4520 Timer 0 overflow

[Rajinder]

Hi
I am using MikroC compiler for the PIC18F4520 family.
I want to know how I check if TMR0 has overflowed?

I have seen on a PIC16xxxx device it is just as TMR0, the following are snippets of code for a PIC16F device :-

i.e. TMR0 = 0 /*clear TMR0*/
while (TMR0 < (int) 500/2.048))

How do I do the same for the PIC18F4520 in Mikro C. I can't just type TMR0 as the compiler reports an error.

Any help would be greatly appreciated.
Thanks in advance

 

[Minder]

Pic timers have a Interrupt flag on overflow, this can be tested, it has to be cleared once read, this occurs whether the int enable is set or not.
I only use Assembly but there must be a simple way in C.
M.

 

[JWHassler]

Post the offending code section, including errors, inside 'code' tags

 

[Rajinder]

Hi
Thanks for the reply.
I will post the code today. I thought thst i had it cracked by using TMR0L. However it still doesnt work.
I will post it later today.
Thanks

 

[Rajinder]

Hi
I have attached the code. It is a reaction timer.
The start LED lights after 2 seconds. Then you have 200/2.048 seconds to hit the button.
If you do then the success LED is lit.

I am getting the success LED on all the time. I am using the internal oscillator set to 500KHz. The LED will light when a 0 is output on the PIC I/O line.
Can anyone help?
Best regards
Raj

 

[Arouse1973]

You need to comment your code so we know what you think the code should do. You need to do this with all your code.

 

[Rajinder]

Hi
I can send it again with more comments.
Thanks

 

[Minder]

To check for TIM0 O.F. is a simple check of TMR0IF in INTCON.
If using it to interrupt then it should be cleared immediately after.
M.

 

[Minder]

Also set TMR1IE in PIE1.
M.

 

[Rajinder]

Hi all
I have already tried the suggestions that you have mentioned.
Clearing the timer0 overflow flag and setting both global and peripheral interrupts.
For some reason i get the success LED switch on all the time.
I have also tried switching timer0 on by using TMR0ON = 1. I am sure this is not needed as the timer increments on the internal prescaled clock.
Thanks in advance.