LPC2129 died, but why ?

I have one question.

What happens if I send data from one pin to another directly without any resistor?

Please answer if one is input and other output, and when both are output (short connection).

We think that's what happend.

Thanks!

Ivan

Reply to
Mad I.D.
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You didn't like my earlier answer :) ?

To quote

"If they are both set as output, maybe. If at most one is set as an output then no. Even if both are set as outputs they would have to be set to different polarities to cause damage.

It's possible that switching transients from different edge timing could cause a problem if both are switched at the same time but I doubt that the transient would be long enough."

Robert

Reply to
Robert Adsett

It is very rare to need a resistor to connect an input to an output. About the only time is when driving different voltage level ports like a

5 Volt output port driving a 3.3 volt input port, but if both are on the same chip I doubt it.

Connecting an output port to an output port might kill one of the ports but I doubt it. I have done this by mistake a number of times with no ill effects. As I said, it might kill the specific port but the rest of the chip should operate.

If the whole chip is unresponsive, I would look at stuff like the clock generator setup or maybe the program got corrupted by interrupting the flash operation. An outside chance would be ESD or static shock damage, I have killed a few parts this way through the years.

Good Luck, Bob

Reply to
BobH

On Tue, 26 Sep 2006 22:22:21 +0200, Mad I.D. wrote: /cut

Thank you Robert and Bob.

When I try to access the chip via Philips flash utility I get "Can't read device, device error etc.

When I try to access the chip via JTAG I can't erase or download the flash in it by I CAN DEBUG CODE ALREADY IN. I get "prefech abort" after around

100 instruction. (CPU fetches instruction which can't execute).

So if I can't erase the flash either way it's dead althrough CPU is operating :-(

Ivan

Reply to
Mad I.D.

You might want to ask again in the yahoo group. This question comes up fairly often. The debug failure could just be a program bug or it could be a JTAG issue, but more information would be needed to track that down.

The serial ISP problem sounds exactly like what you would get if you are not pulling down the ISP pin. In that case you can download into an unprogrammed chip but not again after the first download.

As far as programming via JTAG the obvious question would be what SW are you using? I don't use the JTAG for programming but others do, so if they know what SW and HW you are using they may be able to help further.

Robert

Reply to
Robert Adsett

On 27 Sep 2006 16:10:50 -0700, Robert Adsett wrote: /cut

Keil uVision3 A man from Keil will come next week and take a look at the board. If the CPU si dead we will try to replace only the CPU. Thanks for your answer.

Reply to
Mad I.D.

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