ICP with MCB900

[Ayberk]

Hi

i know there is a lot of topic about this issue but in my problem  there is something different

now i programmed the lpc935 with the 1.4 prog90x.hex get it on the run mode then plugged the lpc922 as shown in app 2 with 2N2222 (icp app for mcb900) and check the device signature it is alright and then i program it programs  perfectly i unplug mcb 900 and power up my chip and so program works ok

but when i try to do this again i get the FFs  for 2 hours and some thing happens and it works again so on and on   it is 47 hours now and i am loosing my hope about theese products

HELP Please

[Andy Ayre]

FFHs means the LPC922 is not entering ICP mode.

When you unplugged the device and plugged it back in check that nothing came lose.

Also did you plug it back together correctly?

I would try some continuity testing between the LPC935 and the LPC922 to verify the circuit is still intact.

Also check the power supply being applied to the LPC922 to make sure it is within spec.

Next check that the LPC935 still works and you didn't accidentally damage it in some way when you were taking the LPC922.

Finally check the ICP signals using a scope and match them with the datasheet.

[Ayberk]

After your msg  i made every thing soldered down and i am still getting FFs also i realized that i am using lpc936 instead of lpc935 because that one does not work at all i have another lpc938 is this a problem

[Andy Ayre]

I'm not 100% sure but I think that the bridge code should work on any of those devices. Just pay additional to the variations in the pinouts.

[Ayberk]

in 1/15  it works but in others no chance i also cannot program lpc922 with ISP when i put it in the socket (dil) and remove LPC936

but i can program 936 and 938 perfectly any time

[Andy Ayre]

Is the LPC922 pin compatible with the LPC936/938? I'm not sure but a quick check of the datasheet should tell you if you can simply drop it into an MCB900 for programming.

Did you check the voltages and put a scope on the ICP communications?

[microjoe]

I have similar problems. I can't program a LPC922 or read the Device ID reliably either.

I am using the MCB800 as a bridge. I have check the wiring 100% and 100 times and I get approx 2.5 volts at the processor.

When programming I remove a set of links which isolates the the circuit from the programming pins Vdd etc. Other pins of the processor remain connected.
I've scope'd the programming lines. I get clocking pulses and data from the programmer but there are times when the data lines go high which I assume is when the LPC922 is not responding.

I have managed to read back the device ID on a couple of occasions and then when I had some useable code I managed to program it. I'm not sure if the code runs properly or not. After progamming I could not read the device ID again.

My guess it that the processor is not entering ICP mode reliably.

Where can I find the ICP programming spec. I've looked but can't find it.

Any other comments and help would be useful

Thanks

[Andy Ayre]

I believe there are some ICP application notes on the Philips web site, and there is a document about connecting the ISP to ICP bridge to the ICP target device on the Flash Magic web page (see third party section).

Hope that helps.

[microjoe]

Thanks Andy,

I've studied most of these documents.

I have progressed further and am getting reliable ID reads but have problems programming.

I have started a new thread entitled  "ICP and LPC922".

I'm getting a little disheartened with it all.

I've used emulators and other embedded micro's for about 10 years now and this one has caused me the most problems. In the end I hope I can say "Ah! Now I understand"

Regards
Microjoe