Problem with 16F648A

[ngeronikolos]

I do not manage to fix my problem.I add the CMCON = 7 to disable comparators...BUT NOTHING.

But I found something strange and I would like your advice.
I use Microcode Studio Plus 3.0.0.5, compiler PBP 2.47, programmer Pickit2.
I compile my code and I program my pic with the .hex generated file.After that I read the pic and the .hex file is not the same(same changes).

LOOK the attaches file

[falingtrea]

Since you are running at 3V you may have an input level problem. If the IF PORTA.1 = 1 never goes true, the hardware just may not be seeing the proper level. If the input pin is "TTL" level then it needs a voltage level of (.25 VDD + 0.8V) for a '1'. If it is a schmitt trigger then it needs at least 0.8VDD for a '1'. Sometimes it is the simple stuff you need to check.

[ngeronikolos]

falingtrea,

The condition IF PORTA.1 = 1 never goes true either using 5vdc.I do not think that is level "1" the problem.

I will try to de-install the Microcode Studio Plus + pICKIT2 because it seems to me that the problem is from the pc.

If someboby have any other idea please advice

Regards
Nikos

[falingtrea]

falingtrea,

The condition IF PORTA.1 = 1 never goes true either using 5vdc.I do not think that is level "1" the problem.

I will try to de-install the Microcode Studio Plus + pICKIT2 because it seems to me that the problem is from the pc.

If someboby have any other idea please advice

Regards
Nikos

This may be a stupid question but have you verified that the signal on PortA.1 is working the way you expect it? What is driving this pin? If it is some kind of open-collector output, for instance, it needs a pullup in order to generate a '1'. I always check the hardware before I assume there is a problem with the software. I can't remember how many times I have put the wrong kind of signal on a pin and wondered why the software did not work.

[ngeronikolos]

Finally falingtrea show me the way to solve my <<stupid>> problem.
I add pull down resistor to PORTA.1...and that's it.ok

HARDWARE
Thanks boys
Nikos

[falingtrea]

I do not manage to fix my problem.I add the CMCON = 7 to disable comparators...BUT NOTHING.

But I found something strange and I would like your advice.
I use Microcode Studio Plus 3.0.0.5, compiler PBP 2.47, programmer Pickit2.
I compile my code and I program my pic with the .hex generated file.After that I read the pic and the .hex file is not the same(same changes).

LOOK the attaches file

If you look closely you will see that from address 0 to 2FF the data is the same. After that the difference between the files is that the read is showing all the blank locations of the total memory for the PIC device. This is normal.