Lpc2000

> Exactly. If the vector table at the beginning of user flash 
doesn't 
> checksum correctly, the chip goes into bootloader mode after reset 
and 
> you can reprogram it over the serial port even if P0.14 is 
permanently 
> tied high. As you say erasing the first sector is probably the 
easiest 
> way of corrupting the vector table.
> 
> BTW on a (sort of) related note, the current version of lpc21isp 
doesn't 
> work on big endian systems like Macs because it calculates the 
vector 
> block checksum incorrectly causing the device to always enter the 
> bootloader on reset. I wrote a patch which fixes this and sent it 
to the 
> author but haven't got any response. There's a copy here:
> http://www.alexholden.net/misc/lpc21isp-byte_safety.patch
> 


I kinda misinterpreted the chksum check process (at reboot) and 
erasing the 1st sector but the last 2 comments by Alex & Robert 
cleared that up bigtime. Thanks. There's more than a way to do ISPs 
afterall :). Thanks for the patch Alex. It's very helpful stuff. I 
had a very hard time finding ISP-related source code to play with 
until now. Trying out lpc21isp might make my day.  





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