Post by thread:!!portB interrupts still a problem

On Tue, 12 Mar 1996 12:22:46 -0800 Scott Dattalo wrote: > >The code looks O.K. Perhaps there is another, simpler problem. For example, do you know if your >'65 is running? Are you using an in-circuit emulator? If not, are you sure the part is getting >programmed correctly? When you use the scope to look at the signal, do you have a storage >oscilloscope? If not, you'll never see anything unless you use the Port A output as the trigger >source; in which case you'll at best see a faint trace across the screen. > >Suggestions >1) Verify your test set up is functional. The easiest way I can think is to create two versions of >your code: the first outputs a logic 1 to port A<0> and the second a logic 0. If they both perform >the same then hmmm.... > >2) Instead of pulsing port A, why not toggle it? This way, you can at least see the current >state with a DMM if you want. > > >Without more info, this is the best I can do. > >Hope this helps > >Scott > Hi Scott Thanks for replying I have tried to take the same code (to which I added a GIE) and delete all parts of the code which relate to port B and the other ports leaving only Port A setup and the test. The code works perfectly and I can see it on the scope (which by the way is a Tektronix digital scope). This leads me to believe at this stage that somewhere in the portB setup there is something that is affecting port A. By the way the simulator (I do not have an emulator) shows it working fine on the code with the portB interrupts. I still remain mystified although I am sure that when I discover what it is I will fell like an idiot. Moshe PS anyone else out there got any suggestions? ------------------------------------- Name :Moshe Fish E-mail :spam_OUTmfishTakeThisOuTnetvision.net.il Date :03/13/96 Time :14:15:28

Moshe Fish wrote: > > I have tried to take the same code (to which I added a GIE) and delete all parts > of the code which relate to port B and the other ports leaving only Port A > setup and the test. The code works perfectly and I can see it on the scope > (which by the way is a Tektronix digital scope). Hard to go wrong there... > This leads me to believe at > this stage that somewhere in the portB setup there is something that is > affecting port A. By the way the simulator (I do not have an emulator) shows it > working fine on the code with the portB interrupts. Here are a few more ideas. 1) Are you certain that your pic include file P16C65.INC is O.K.? Specifically, it's possible that your PORT B definitions may be fubarred. 2) Have you tried another target PIC16C65? Maybe you have a bad chip. 3) Where in your code did you enable GIE? Since the interrupt routine does not save the STATUS register and reinitialize it for its on use, there's a chance that RP0 is in the wrong state when the interrupt occurs. Consequently, your write to PORTB would instead be going to TRISB; ditto for the PORTA write. This could change the PORTB inputs to outputs! > I still remain mystified although I am sure that when I discover what > it is I will fell like an idiot..............->feel? or fail? That's O.K. all idiots eventually fell (fail). However, I'm sure your no idiot! Scott