ICD2 PIC18F452 ICSP

[digitalfreak]

Hi,

I am newbie to ICSP, iam trying to use it using ICD2 and MPLAB.

Did a quick serach and gone through the ICD poster, got fairly decent idea. I have seen mixed opinions about loosing pins PGC/RB6 and PGD/RB7

In my circuit RB6 and RB7 are connected to ChA and ChB of an optical encoder, hence I will be configuring them as inputs. - And I cannot avoid doing this bcoz I am maxed out on I/O's.

Iam planning to have a manual switch for both lines when doing programming. My question is do I need any configuration of bits or reassign IO's etc...for using ICSP...other than NOLVP

bottomline: Code-wise is it OK to have RB6 and RB7 as inputs?

Can ne body send me snippet of how these pins look like in code when in programming..

thanks,
sorry if this is something stupid.

[carmarmu]

I think that´s not possible.
I believe that always you must use those pins, since when you include the order to use the ICD2, a small program is recorded in PIC,wich serves to communicate with the PIC through those pins when it´s in Debugger mode (in addition to programming it), therefore, if I´m not mistaken, you will always have to use pins PGC and PGD of your piece (it´s the piece that´s). If I´m mistaken,correct to me and thus I learn something new, but I believe that not it can.
Greetings.
_________________
**CaRmArMu** Valencia (Spain)

[treitmey]

You can not reassign programing to other pins.
You must use what is in the spec sheet.
I use B6 and B7 for inputs all the time. You may be able to also. You may not even need a manual switch.
The easiest way is try it and find out.
As for debuging, when you debug those pins will be used for debug and the main function of those pins will be lost. But you may be OK with that.
Here is some more info.
Pay attention to the voltage levels on mclr.
http://ww1.microchip.com/downloads/en/AppNotes/00910a.pdf
Inside this reference is another reference to ICD AppNote.
and
http://ww1.microchip.com/downloads/en/DeviceDoc/51331B.pdf
see botom of page 22

[Mark]

If you are just doing in-circuit programming then just disconnecting the pins for programming is fine. If the connected device will not affect the signal from the ICD then you do not even need to disconnect the device. The micro always comes out of reset with the GPIO as inputs so even if you used those pins as outputs, you'd be safe.

[digitalfreak]

[digitalfreak]

thx Mark thats exactly what i want...

my prevous reply was sent before reading urs!

have fun