Lpc2000

Robert, 

> The Philips ARM7 implementation can not be debugged through 
> Reset for a very simple reason, it is called code security.
> 
> At reset, all debug channels are disabled to ensure that 
> nobody can break into the chip. Then the code security memory 
> cells are evaluated. If security is not desired by the 
> programmer, the debug options are enabled. 
> 
> If Debug options would not be disabled in the beginning, 
> there would be a time window that can be used to force entry 
> into the device. 
> 
> ARM7TDMI, the core itself could be debugged from reset, 
> correct but we prefer a higher security over minor 
> restriction for debugging. 

Surely programming a fuse in the device would be enough to enable
security as found in so many other micros?  The MSP430 is insecure until
its fuse is blown.  The AVR can be similarly kneecapped.  There are
other ways to achieve the same level of security, one would assume.

--
Paul Curtis, Rowley Associates Ltd  http://www.rowley.co.uk
CrossWorks for MSP430, ARM, AVR and now MAXQ processors