RA6 & RA7 I/O setting on the 16F88

[PICante]

I would like to use RA6 & RA7 on the 16F88 as standard I/O. I haven’t been able to figure out (the datasheet is not helping me a lot) how to set the CONFIG1 (FOSC) bit 4, 1 and 0 to (%1XX00) without disturbing other settings. Can someone please explain how to accomplish this.


Thanks!

[mackrackit]

You can find all of the config settings in the *.inc file for the chip by going to program files, microchip, mpasm suite.. find the *.inc for your chip , open in notepad, go towards the end.

Looks like
_INTRC_IO

That should have the internal running and the two pins as I/Os.

[BobK]

Hi PICante,

I had the same problem with the 16F87 which is sister chip to the F88. Do a search for my thread entitled "Internal Osc help" dated January 12, 2007 and look at Bruce's reply. It worked for me.

HTH,

BobK

[mackrackit]

Now I am confused.

I went and read the post Bob mentioned and tried it. Did not work.

I do not have a 16F88 laying around, but set up a project in MPLAB.

When I use _INTRC_IO and read the config register I have the expected results.

When I use _INTRC_OSC_NOCLKOUT I get an error and the config register says LP.

[skimask]

Now I am confused.
I went and read the post Bob mentioned and tried it. Did not work.
I do not have a 16F88 laying around, but set up a project in MPLAB.
When I use _INTRC_IO and read the config register I have the expected results.
When I use _INTRC_OSC_NOCLKOUT I get an error and the config register says LP.

Unless I'm wrong, the P16F88.INC file in the MPASM doesn't have that config directive listed.
It's got these listed for oscillators:
;Configuration Byte 1 Options
_EXTRC_CLKOUT EQU H'3FFF'
_EXTRC_IO EQU H'3FFE'
_INTRC_CLKOUT EQU H'3FFD'
_INTRC_IO EQU H'3FFC'
_EXTCLK EQU H'3FEF'
_HS_OSC EQU H'3FEE'
_XT_OSC EQU H'3FED'
_LP_OSC EQU H'3FEC'

I think you want INTRC_CLKOUT.

[mackrackit]

We are looking at the same thing.

I picked _INTRC_IO because I think that should make the pins I/Os.

So what was Bruce talking about in Bob's post? The *.inc s are pretty much the same for the 88 and 87.