Lpc2000

> 1) Try turning off the MAM to eliminate 
> this from the set of variable. 

Already using MAM_OFF.

> 2) Are you using Thumb code? If so, perhaps the .data assignment is 
> throwing away the thumb attributes.

Nope, 32b code.
 
> 3) A Prefetch Abort means that there is no memory available at the 
> address you specify (like a data abort, but for instructions).
> 
> The code 
> 
>     LDR  PC,[R5,#0]
> 
> should be loading the pointer from this address
> (ie. R5 + #0 should be a 32-bit value that is the pointer
> to the code).
> 
> Check that the address actually contains the **pointer**
> to the code you want to execute and not the actual code itself.
 
Now we're getting somewhere.  I think this is the problem.  I want it 
to jump to and execute at the 0x4000000 adr.  There is no pointer 
there.

> Perhaps try
> 
> static const (*fnptr)(void) = IAP_Test;
>  ...
>  *fnptr();

That gives a compiler error:

main.c:107: error: invalid type argument of `unary *'
D:\GNUARM\bin\make: *** [main.o] Error 1
 
> which should put the pointer in the literal pool and generate 
> different code.

Yeh I think this is on the right track.  I need to get my C syntax 
correct here to generate a long jump directly rather than loading a 
pointer.  The function is at 0x40000000 not a pointer to it.

If you have any other ideas for this, please pass them on.  Meanwhile 
I check my C books to try to figure out the needed syntax.

Chris.