Lpc2000

Has anyone ever received a conclusive reply from Philips concerning the 
reason for the slow GPIO? I just would like to know why this port is so 
slow, I am curious. Initially I thought it had to do with the set/reset 
logic and the goal of  synchronizing the output port. But the port is 
still slow even if I write directly to the IOPIN or IODIR registers.

The sequence below where r6 and r4 are loaded with bit patterns while r0 
holds the IOPIN address runs 7 times slower than the CPU clock with a 
VPBDIV=1.

    str    r6,[r0]
    str    r4,[r0]       
    str    r6,[r0]
    str    r4,[r0]       
    str    r6,[r0]
    str    r4,[r0]       


Something that I miss from the LPC21xx datasheets is a good old logic 
diagram for the GPIO which most micro datasheets normally feature.

--
Peter Jakacki