ICP problem LPC922 and MCB900

Started by rkr76, April 10, 2008, 02:54:17 PM

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I'm having problems re-programming a P89LPC922. By accident I programmed the LPC922 with the wrong hex-file and erased it...

First I tried to program it by using the ISP method.I connected it by Vdd,Vss,Txd,Rxd,RST
I'm using a new MCB900 board. I was able to program a P89LPC935 in the on board chip socket using the newest Flash Magic.
When I try to read the signature I get a message that I should try to reduce the baudrate settings. That doesn't help...
I measured signals, reset pulses three times, the power is 3,3V, and TX and RX show data. I guess ISP won't work because the LPC it completely erased? So no ISP protocol anymore....?

Then I tried to reconfige my MCB900 into a ICP-ISP Bridge programmer. I used the prog90x.zip form this site to program the LPC932 on the MCB900. When I switch the MCB900 to the run-mode, the LED goes on, like it should...

When I try to connect to my board, I get a manufactor ID and device ID of 00 ... It should be 15h or something like that...
What am I doing wrong? I'm having this problem with all my boards.

The MCB is connected to m board using P0.4, P0.5, P1.5 VSS and P2.3 for VDD

When I measure with a scope on P2.3, nothing happens.... When I switch on the MCB900, I see that P2.3 becomes 3V3, and stays there...To enter ICP it should switch the power on and off? I'm using a FET to switch VDD on my board, that should not be the problem.
The output on P2.3 doesn't work...

My questions:

- the documentation on the site uses a LPC932 for the ISP-ICP bridge. I used a LPC935 instead. Can that be a problem? The pinouts are the same...
- What else can go wrong? Does anybody have some advice?





great article, I did use that information...
The weird thing is that the P2.3 line does not switch at all....
When I switch on the MCB900, the P2.3 line becomes 3V3 and stays 3V3....
How should the signal look like? Sometimes when I switch on the MCB900 I see that P2.3 becomes 3V3, drops for a few uSec, and then stays 3V3.......It drops just once...

The reason I use a MCB900 is that I use it for more things... ISP for example.

Je Gold

So you are trying to program a LPC922 using ICP method..

To program ICP method... after Vdd turn-on of LPC922,  immediately  7 reset pulses must be applied (50uS)

Hence P2.3 turns off Vdd_LPC922 and then turns on Vdd_LPC922 and RESET pulses are applied to the LPC922

The full ICP document is available on the LPC900 Yahoo group.

Try examining the P2.3 output of the MCB900 without the MCB900---ICP bridge hardware... with a few replacement LPC932/LPC935 micro's in case P2.3 is faulty.

(I managed to examine the ICP bridge code... and P2.3 seems to be quasi bi-directional)




I have approximately the same problem, do you found a solution?