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Messages - sbjoshi

#1
Sender: S B Joshi

We recently (May 2010) faced same problem (of P89LPC936 programming only once and then not entering ISP mode again).

I will try your solution of entering debug mode using F1 key and then try kickstart ISP by asking for signature. I hope it will work.

To be on safer side, we have added a UART based command (to our application code) to facilitate setting the Boot Status Bit by using "89LPC935 - Boot Loader activation by software" application note authored by "R Raghunathan / 12 July 2009" based on "original idea by Erik Malund and initial assembly implementation by Lex Timmerman.". It worked for us very well and it enables graceful entry to ISP mode, overriding the 3 reset pulse ckt of MCB900. We have added some code to restore boot vector to 0x3F, in case it is not read as 0x3F.

Reporting a new issue with LPC936 as below:

We also observed that if external reset pin is disabled using FlashMagic then neither ISP runs, nor, my application code runs. The P89LPC936 enters erratic mode and keeps echoing odd characters to whatever I type in Hyperterminal at 9600 baud. Can anyone help us for this, please.

Thanks in Advance.

Suresh Joshi