[Diy_efi] GCC/ARM LPC21xx assist needed for Donegan ECM/EFI :-)

[Ian Molton]

Steven P. Donegan wrote:
> I didn't even really understand what FIQ was, now I do, since I will
> only need 1 low speed frequency source for the current project (max Hz
> is <20k) I likely just need a more standard IRQ setup on the CCP/TMR
> setup.
> 
> Any further suggestions gratefully accepted :-)

Its possibly worth characterising the latency of the chips I/O lines. on 
some ARMs (notably intels hacked up POS the 'XScale') the turnaround 
from a state change on an input, to actually setting an output had a 
quite alarming delay...

(A signal generator and a 2 trace 'scope would be useful here...)

if all you're after is a frequency source then yes, the chips internal 
clock registers should be more than capable - in fact I'd have thought 
any half decent RTOS could provide a garaunteed programmable timer ?

If you get some hardware to me, I'd love to help you hack on this one. 
My development environment is all GNU/linux/GCC here. You can see some 
of my stuff over on http://www.mnementh.co.uk/eseries/

Have fun :)