Lpc2000

Hi, 

> I'm evaluating the Keil MCB2140 board and uVision3 to read 
> serial input and transmit it to the USB port of a PC.  Seeing 
> as how Keil generously already wrote software to mount an 
> MCB2140 as a USB HID device and separately to communicate 
> with interrupts via UART, you'd think this would be easy.

Why not implement a CDC class, just as I did?

> It's not for me.  I've pasted the two programs together and 
> I'm tracking down a resulting bug that locks up the system.  
> The bug is a result of some memory location being incorrect.  
> I can't say too much on the bug itself because I can't trace 
> the program from the moment of power-on.  That is where I need help.

Ok.

> The USB operation requires unplugging the USB cable to the 
> board and plugging it back in so that the USB PC host will 
> begin communication.
>  Since this powers off and on the board, I expected the board 
> to reset at 0x0.  Again, I was wrong.  Power-on does not do 
> what pressing reset does.  I'm guessing that the bootloader 
> (v2.11) remaps something, but I really don't know.  There is 
> no battery visible on the board to preserve a volitile memory 
> location, and the bug appears whether the JTAG is connected 
> or not (to weed out JTAG power preserving state).

Why not power the board and then you can debug USB insertion and trace
things...  Alternatively, use serial I/O to dump data.

> Does anyone have suggestions, keywords to search for, or 
> articles to help me understand power-on operation and how to trace it?

POR will either go into the bootloader or into your own code.  Check the
ISP jumpering.  If you want a nice 2148 board, try the IAR LPC2148 board
which Olimex made for them.  It's a nice board, has an LCD for debugging
if you need it, and can be powered from various sources which allows you
to easily debug self-powered devices.

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