P89CRD2HBA Returning "R" when programming....

[codematic]

Greetings,

I have had a few of my MCU's "die" in this described manner, and am a little confused as to how this can happen...

I can communicate with the bootloader, read the settings, but when i attempt to actually flash the device it is failing.  (Which means that it is sending back and "R" rather than a "." character when the programming line is sent).

Does anyone know A) How this can Happen, or Why  B) How do i recover ?

Thanks, !
Codematic

PS : Your flashmagic utility kicks major butt.



Post Edited (05-26-04 03:58)

[Andy Ayre]

Thanks for the compliment.

Returning an 'R' should not be fatal - i.e. result in the device no longer working.

Are you pulling both P2.6 and P2.7 high during reset into ISP mode? If not then make sure you are as that can cause funny things to happen.

If that does not help and you can spare another device, can you please perform the last resort steps in the Flash Magic application note "what to do when ISP does not work". That will give me a better idea of what is going on.

Thanks

[codematic]

Thanks,

Just as a point of disclaimer, i see this issue with your software utility as well as my own perl script that implements the protocol. That is how i know the "R"'s are being sent.

So i think your utility is not the issue, but rather my use of these CPU's.

Looking at my layout, i can see that 2.7 is tied high, but 2.6 is being used as a clock bit for another device. That could be the cause of the issue.

Is it your experience that when a device is sending "R" for programming that it can be recovered then. (and hopefully via ISP...) ?

Thanks For your help,
-Lenny

[Andy Ayre]

Well, the only way a device cannot be recovered is if the boot vector is reprogrammed to a non-default value or the device ends up in some odd state because of an electrical problem (pin voltage levels, glitches on /rst, vcc, gnd, xtal pins etc.). By not recovered I mean that you cannot enter ISP mode again if you reset or power down the device.

Not having the voltages on P2.6 and P2.7 correct can cause these devices to behave oddly, so I would try fixing that first.