Lpc2000

I have a strange problem with my ISR jump failing after I STOP/GO the 
CPU through the debugger.  I have a single ISR running off Timer-0 
that trips 10X per second.  When I start the code from 0x0 it runs as 
intended forever calling the ISR as it should. But when I use STOP, 
and then GO, the ISR never gets called again.  

I would have expected that it should jump into the ISR as soon as the 
GO is given since the Timer-0 Int flag would have already gone off.  
I don't understand why the ISR stops working after a STOP/GO.   It 
just quits branching into the ISR. The flags all say it should.  
Timer-0 is still running correctly.
 
Does breaking in with the debugger shut down ISR's somehow?
What am I missing?
 
Chris.

>> I have a strange problem with my ISR jump failing
>> after I STOP/GO the CPU through the debugger.

Solved.  Some of the regs, like the T0IR I think, have a nasty 
behaviour of clearing after they are read.  In the debugger I have 
the Registers window open and after a STOP it reads the Regs.  That 
killed the int flag and thus no more jumping into ISR.

So it works now if I shut the regs window.

I was aware of this Read-Once issue, but I guess I thought that the 
JTAG was ported into the CPU and could get at the reg values 
directly.  Kind of like the old bond-out CPU setups.  Not the case.  
Live and learn.

Chris.