Lpc2000

--- In lpc2000@yahoogroups.com, "Hossam Alzomor" <zomorh@...> wrote:
>
> Hi
> 
> I think that fast IO is a feature in recent released versions of ARM.
> It's an IO's connected directly to AHP of AMBA bus and not throgh APB
> You can check ARM web site
> 
> Salam
> Hossam Alzomor
> www.i-g.org
>
Close but not quite correct,

some other devices of other manufacturers have connected the I/O to 
the AHB bus but there are still some delays on the AHB although it is 
definitely faster than using the APB (= VPB). The fastest bus in an 
ARM7 system is the local memory bus. 
The Philips LPC214x and LPC2101/2/3 have I/O pins connected to the 
local bus. 

Max frequency you can achieve is CPU/4 so, a 60 MHz device can 
generate a 15 MHz output. Keep in mind that this is all CPU driven and 
while generating a 15 MHz output, you are not going to do anything 
else. 

Robert