Could not read RAM: No responce from the ICD Data in buffer:

ids@ids-houston.com · Joined: 13 Sep 2003 Posts: 4 Location: Houston, Texas

During Debug I can not read the RAM or ROM Values but everything else I looked at worked fine .

The single step is rather slow.

I am only using a 47K ohm resistor pulling up the /MCLR pin and the RB6-7 pins are only used for ICD interface.

The prototype is running on 3.30 VDC

I am on a deadline and would appreciate help from anyone who is famular with the solution to this error.

I need to monitor the RAM values during single stepping through the program.
_________________
Embedded MPU's are cool.

PCM programmer · Joined: 06 Sep 2003 Posts: 21708

Just a suggestion for something to try:
Change the demo board so the PIC runs at 5v.
See if that makes it work.

ids@ids-houston.com · Joined: 13 Sep 2003 Posts: 4 Location: Houston, Texas

The other components in the embedded circuit all run at 3.3VDC and if I were to raise the VCC to 5.0VDC it would blow some of them.

I will try by unsodering them first.
It is a lot of work but it can be done.

I did not hookup the B3 connection to the ICD cable due to a limited number of I/O, would this have anything to do with the problem?
_________________
Embedded MPU's are cool.

PCM programmer · Joined: 06 Sep 2003 Posts: 21708

I did some more research, and I found a Microchip document
which talks about your problem. Go here,
http://www.microchip.com/1010/pline/tools/picmicro/icds/mplabicd/index.htm
and download this document: Technical Notice ETN 21

ids@ids-houston.com · Joined: 13 Sep 2003 Posts: 4 Location: Houston, Texas

I am using the CCS ICD-U40 for development, I do have a Microchip ICD2 but I was never able to get it to function on any hardware with XP.

I would like to stay with the CCS ICD-U40.

I am also using the CCS PCWH Compiler IDE Version 3.41, and PCB Version 3.182

I have rerouted the rb3 to the pin 6 of the programming header and moved the I/O signal I had routed to another pin, and I did change the set_tris statements to reflect this change.

I did read the artical you referenced to and notice a statement of " disable the LVPM mode.

Is this valid for this system as well?

It would be difficult to make th change over to 5VDC, but I will do it if it is nessassary.

I like to debug watching the MPU registers.
_________________
Embedded MPU's are cool.

Mark · Joined: 07 Sep 2003 Posts: 2838 Location: Atlanta, GA

If you are not using the low voltage programming mode then you should definitely disable it. It is a common error that many people encounter. If the level on the low voltage program pin changes, it will accidently put the device into programming mode.

As for the ICD2, did you try this with MPLAB? It works fine for me under XP.

Note that the CCS ICD must be used with their IDE. I have not used their ICD so I can not comment on it.

ids@ids-houston.com · Joined: 13 Sep 2003 Posts: 4 Location: Houston, Texas

Yes I did disable the LVPM.

I have also unplugged everything which could be damaged by the 5VDC and I still get the same error when I select the RAM debug list

I am working with the CCS ICD-U40 and the CCS IDE.

Do you know of anyone who is working with this combo that I can contact?

The only thing hooked up to the ICD at this time is the MPU.

All other I/O pins are open.

Got to go and watch a movie, thenks for your assistance in this matter.
Have a great Holliday season.
_________________
Embedded MPU's are cool.