Lpc2000

At 07:47 PM 7/7/04 -0700, you wrote:
>It would be nice if Philips provided a reliable (as in supported)
>mechanism to get back into the bootloader from user code.

Not to pick on you in particular, but this seems an awful lot of angst over 
bringing out one more connection.  If you are going to allow ISP after 
potting you have bring out a minimum of 3 signals anyway (TxD, RxD and 
Gnd), 5 if you provide power and control the reset.  Adding 1 to control 
P0.14 really doesn't seem like a big deal.  Actually the only element that 
comes to mind is if you are reusing a connector with predefined meanings 
and can't reuse an existing pin definition for programming.

In addition, it is possible to get into a situation where the part is 
partially programmed and therefore won't enter ISP mode automatically but 
there isn't a valid user program to force a shift to ISP mode.  If P0.14 is 
not brought out in some fashion then any boards that get stuck here will 
have to be tossed.

I think if you need to be able to program parts reliably w/o using P0.14 
you will need to devote the first sector to a code that is never erased and 
provides a way to program the remaining 14 sectors with the application 
code.  The first sector might also provide other support code (maybe 
diagnostics, a way to initialize the hardware to a good, safe start 
condition etc...

Robert

" 'Freedom' has no meaning of itself.  There are always restrictions,
be they legal, genetic, or physical.  If you don't believe me, try to
chew a radio signal. "

                         Kelvin Throop, III