Re: [Gumstix-users] Overo GPIO minimum switching time

[Giovanni C <uc...@gm...>]

Thank you for your help.

On the scope I measure a complete period of 1.4usecs, which means high for
0,7usec
and low for 0,7usec.

I thought that 600MHz could be fine to run a parallel interface at
10MHz/20MHz.

Which is the maximum speed of MMC bus?


ScottEllis wrote:
> 
> Unlikely that BT is interfering with the timing. That irqlat module
> toggling test only takes around 400 us. I doubt it got preempted. You need
> to do the measurement with a scope. If by some unlikely chance it did get
> preempted, you'd see it in the waveform.
> 
> As for trying to bit bang an 8-bit parallel interface at 5 MHz running
> under an O/S on a 600 MHz system, I think that's very unlikely, assembly
> or not. You should look at one of the parallel controllers on the OMAP
> like the GPMC (others?). That will give you some hardware (and DMA)
> support.
> 
> 

-- 
View this message in context: http://old.nabble.com/Overo-GPIO-minimum-switching-time-tp30890534p30902930.html
Sent from the Gumstix mailing list archive at Nabble.com.