Need a sanity check

[bfmitch]

Maybe I'm missing something. I'm using a PIC18F452. I'm trying to use bit E2 (which is also AN7 and CS for the PSP) as an input. The problem is, that it always drags down the 5 volt signal it's being fed to about .25 volts.

First I checked the board. Looked at all the traces, etc... and they're just fine. If I remove the PIC chip, the signal doesn't get dragged down. So it must be how I have the PIC intialized.

I set the ADC parameters so that bit is used as a digital IO line and used TRISE to make sure it was an input. No joy.

I disabled the PSP using setup_psp(DISABLED), the signal is still dragged down.

I used TRISE again to disable the PSP and set the IO directions. Still not working.

I tried using output_float to see if I could at least get it to go high impedance. You can guess it didn't work.

Doe E2 perform some function besides the PSP Chip Select and Analog input 7?

I suppose that the chip itself could be the problem. Of course, I won't have another one for a few days.

Any ideas?

[asmallri]

My guess is you have defined a register address incorrectly.

Here is a section of operational code using the PIC18F452 using PORTE (E2 used as an output)

[bfmitch]

My sample PIC18F4525 just arrived. I already had the fuses, etc... worked out just waiting for it to show up. I programmed the new chip, plugged it in and the problem was gone.

Thanks!