Post by thread:Setting up TMR1, what am I missing?

Once again, I must be missing something. I am trying to set up the TMR1, on the '74, as a timer with a prescaler of 4 that will trigger an interrupt on overflow. This is what I have setup so far: Intcon - GIE =1 ;global int's enabled the rest=0 PIE1 - TMR1IE =1 ;enable TMR1IF interrupt the rest=0 T1CON - TMR1ON=1 ;starts timer T1CKPS0=0 ;sets prescaler T1CKPS0=1 ; " " the rest=0 I have had no problems using TMR0, but TMR1 just wont work. My int-service routine just buzzes a buzzer to let me know that the overflow has happened. But, I get no buzz. I am not even trying to desern which interrupt has happened, just buzz the buzzer. Thanks for your help Zach PS I know the buzzer is working : )

Xaq <spam_OUTPICLISTTakeThisOuTMITVMA.MIT.EDU> wrote: > I am trying to set up the TMR1, on the '74, as a timer with a > prescaler of 4 that will trigger an interrupt on overflow. > .... > Intcon - GIE =1 ;global int's enabled > the rest=0 > > PIE1 - TMR1IE =1 ;enable TMR1IF interrupt > the rest=0 > > T1CON - TMR1ON=1 ;starts timer > T1CKPS0=0 ;sets prescaler > T1CKPS0=1 ; " " > the rest=0 > > .... TMR1 just wont work. Zack: Set the PEIE bit in the INTCON register. -Andy Andrew Warren - .....fastfwdKILLspam@spam@ix.netcom.com Fast Forward Engineering, Vista, California http://www.geocities.com/SiliconValley/2499

>>.... TMR1 just wont work. > > Zack: > > Set the PEIE bit in the INTCON register. Thanks Andy, but I had already tried that and it still didn't work. Are the timers peripherals? Any other suggestions? Thanks Zach

>I am trying to set up the TMR1, on the '74, as a timer with a prescaler of 4 >that will trigger an interrupt on overflow. > >This is what I have setup so far: > > Intcon - GIE =1 ;global int's enabled > the rest=0 > > PIE1 - TMR1IE =1 ;enable TMR1IF interrupt > the rest=0 > > T1CON - TMR1ON=1 ;starts timer > T1CKPS0=0 ;sets prescaler > T1CKPS0=1 ; " " > the rest=0 PEIE needs to be set - as already stated by Andrew Warren TMR1CS needs to be 0 (internal clock) T1OSCEN could be turned off for good measure as well Are you remembering to initialise the TMR1H and TMR1L registers - as well as re-loading them when entering the interrupt service routine? Also, did you clear PIR1 - TMR1IF before you enabled the interrupt for the first time (and does your interrupt service routine clear it again?) I did all that, and mine is quite happily giving me a 2mS interrupt... Jim