I can confirm this with a scope. After porting the kernel module from this topic: https://groups.google.com/forum/#!topic/beagleboard/dyuax5415dc
I measured exactly 12.5MHz. Apparently mmap is doing something stupid that slows down the access from user space. On Monday, August 24, 2015 at 5:41:25 PM UTC-7, Charles Steinkuehler wrote: > > On 8/24/2015 7:26 PM, William Hermans wrote: > > > > So this is word of mouth from these very forums perhaps a couple years > ago > > but I do recall someone ( as in someone qualified to know - don't > remember > > exactly who ) saying that technically, GPIO's can be toggled on/off at > > 100-200 Mhz - Using a PRU. > > That's using the PRU direct I/O, *NOT* the GPIO pins. There's a > difference. :) > > Even the PRU can only get about 12.5 MHz out of a GPIO pin, although > it can _easily_ get 100 MHz toggle rates (200 MHz update rate) from > the PRU direct outputs. > > -- > Charles Steinkuehler > [email protected] <javascript:> > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
