Lpc2000

> I'm not sure what's going on here, but I appear to be having a reset 
> problem with the Keil development board.
> 
> I am using CrossWorks for the ARM and a Olimex Parallel JTAG adapter, or 
> a USB CrossConnect (both exhibit the same problem).
> 
> On initial powerup, download of code and debug the code runs as expected 
> (some interrupt code and a counter to indicate that the interrupt is 
> being run).
> 
> If I recompile (with or without change, it doesn't matter) and reload it 
> then sometimes the code won't work. Or will partially work (eg. running 
> in the main loop flashing LEDS ok, but the irq isn't executed -- counter 
> is at 0).
> 
> I've tried various combinations of stopping and reloading, software 
> reset of jtag adapter, etc. Pushing the reset button on the board, etc. 
> The only thing that consistently works is pulling power from the board 
> before reloading. If I have to do that every time I change the code I'm 
> going to go nuts.
> 
> Has anyone seen this before? Or has any ideas?

An idea:

When debugging with JTAG, often the program runs out of SRAM. 
Unless the loader explicitly clears RAM (eg. the .bss area),
then there is a chance that you will see differences between
a cold start (pulling the plug) versus a warm start (any form
of reset). 

So, if you code looks at some variable that you assume to be
zero - change it to explicitly set that variable to zero
(making it part of the data section).

Dave