Lpc2000

> Have you tried talking to the device over a serial terminal 
program 
> like "HyperTerminal" or "TeraTerm"  instead of using the ISP 
utility. 
> You can start by issuing a "?" and then the part would return 
> with "Synchronized"...then would follow the ISP procedure. I think 
> this flow is mentioned in the UM.
> By doing this you can get a more detailed picture of why ISP is 
> failing. If a ISP command fails/succeeds the bootloader always 
> returns a "code".
> Using the code, you can get more information from the part 
regarding 
> this problem.

I've been using the Bray++ Terminal.
http://bray.velenje.cx/avr/terminal/
This comes with DSR/RTS control buttons (Hyterterminal doesn't have 
this) which I need to run my my board correctly. 

The synchronising sequence works, but however I haven't yet figured 
out all the replies for the basic commands:
-Read Part ID (J<CR><LF>) returns a 0x00 but no part ID bytes
-Read BootPart ID (K<CR><LF>) returns an unknown string

>  I know this is far stretch but I had similar problem with another 
> LPC2000 chip and diference was in RS232 chips . STMicro ( MAX3232 
> equivalent ) was not the same as MAXIM or TI equivalent. The same 
> syndrom - ISP would not download code - otherwise all serial 
> communications were OK.

I'm using a MAX3314 rs232 chip to drive both lines.

> It is almost certainly the hardware. Check the signal on the RX 
> line - if it has overshoot or ringing then there will be problems 
> (maybe the capacitors on the RS232 transceiver are bad?).
> 
> An initial design of mine used a high speed gate in the Rx line 
> (TinyLogic) between RS232 transceiver and RX pin. I could 
establish 
> communication but downloads would always fail - in my case 
somewhere 
> in the middle. The fast TinyLogic had spikes at the output 
> (overshoot) - once I removed this device I never had problems 
again.

It very well could be a hardware problem. Both RX/TX signals look 
pretty good to me (clean square wave with no spikes or anything). 
However I notice a -0.1 V to 6V on the T1OUT line, which seems a 
little trivial to me.

Thanks for the replies guys, I think I might be getting closer.

Leighton