Lpc2000

--- In lpc2000@yahoogroups.com, Sten <list@...> wrote:
>
> tah2k wrote:
> > Hi All-
> > 
> > I'm currently experiencing a very frustrating issue with the 
LPC2138 
> > bootloader. I can successfully and reliably use the Philips 
flash 
> > utility to download an image to a blank LPC2138 once and only 
once. 
> > After that, the flash utility is never able to communicate with 
the 
> > LPC2138.
> > 
> > I have been monitoring the recent bootloader thread that was 
> > resolved by manipulating the watchdog overflow flag which, if 
set, 
> > will cause the bootloader reques to be ignored. Unfortunately, 
this 
> > is not the same problem I am having because I'm never enabling 
the 
> > watchdog.
> > 
> > I've been working with an evaluation board for 6 months now so I 
> > felt confident I understood the processor because I never had 
this 
> > issue. Now that I am bringing up custom hardware, I removed 
> > everything from the board except the processor, JTAG, and power 
> > supplies. I thought perhaps my code was inadvertently 
configuring an 
> > I/O pin in conflict, so I modified the application code to 
simply 
> > sit in a loop after disabling interrupts and other basic init 
steps.
> > 
> > The signals to the processor are exactly what I would expect:
> > 1.) The reset line and P0.14 are pulled low by the Philips Flash 
> > application at t=0.
> > 2.) The P0.14 line is held low for about 470mS before being 
> > released, and the reset is held low for about 820mS before being 
> > released.
> > 3.) After these transitions, the processor sees the 0x3F being 
> > transmitted by the flash utility.
> > 
> > So, as far as I can tell, everything is ocuring correctly, but I 
am 
> > unable to access the bootloader after the first initial image 
> > download. I was initially swapping processors, but each one 
behaves 
> > the same way.
> > 
> > Thanks-
> > Tim
> > 
> 
Hello Tim.

As long as the Philips flash utility can drive the \RESET and P0.14 
with DTR and RTS there should be no problem with the bootloader.

-Sergei