LPC2xxx (ARM) GPIO speed

[edaudio2000]

gpio speed

I have an LPC2138 running at 60MHz. However, when I toggle the I/O pins repeatedly (using IOxSET,IOxCLR, or even IOPIN instructions), e.g.

IO0SET = 0x01
IO0CLR = 0x01
IO0SET = 0x01
IO0CLR = 0x01
IO0SET = 0x01
IO0CLR = 0x01
IO0SET = 0x01
IO0CLR = 0x01

The port toggles only at about 160nS between instructions. The resulting assembly shows no extra instructions, and I have also set the GPIO divider VPBDIV to 1. So theoretically the port should be operating at core speed, but it is only running at about a tenth of that.

Is there an intrinsic I/O limitation in LPC parts, or is there a way to run the I/O ports at a higher rate?

Thanks

 

[bobcat1]

lpc2106 assembly fast gpio

Hi

The LPC21xx can't toggel normal I/O faster then 5 MHz.

Whether you like to toggel faster you can use the LPC21xx-001 with the FAST access register


All the Best

Bobi