I think I have grasped it now. You can set individual pins to different mux modes?
On Monday, January 12, 2015 at 7:11:37 PM UTC, Neabex wrote: > > Andy, there are two kinds of PRU GPIO writes, the direct ones, in which > you write to the R30 register, and ones where you have to access the gpio > subsystem, you only need to mux it to the PRU if you're doing the direct > method. > > > On Monday, January 12, 2015 at 9:07:17 AM UTC-8, AndyS wrote: >> >> Thank you for your quick replies. I will work through the examples this >> evening. >> >> Ok. I think I might be getting a little confused of something called mux >> mode5 which looks like it is specific to an example I have been following >> on GPIO from Derek Molloy. >> >> Can I create my own overlays to configure the mux which uses both GPIO >> and PRU IO? ( and the ADC if required) >> >> >> >> On Monday, January 12, 2015 at 4:57:19 PM UTC, Charles Steinkuehler wrote: >>> >>> On 1/12/2015 5:11 AM, AndyS wrote: >>> > Hello, >>> > >>> > I have an application which requires use of the PRU for some fast IO. >>> I >>> > need to use more IO than the PRU can handle, but some of the other IO >>> only >>> > needs to operate in slow time. >>> > >>> > Can I configure the BBB to use both PRU IO and Linux controlled GPIO. >>> >>> Yes. The PRU writes to GPIO pins are not particularly slow unless you >>> saturate the interconnect, but the writes are posted and happen a while >>> after the PRU executes them (apx. 100 nS later). Unless you need >>> critical timings between the direct PRU outputs and the GPIO pins, this >>> shouldn't be a problem. >>> >>> Reads from GPIO pins are another matter. Since it is not possible to >>> post the reads, and the PRU (by design) doesn't execute instructions out >>> of order or perform speculative execution, the PRU core stalls after >>> issuing a read GPIO request until the data is returned from the >>> interconnect fabric (apx. 165 nS). >>> >>> I have timing details in the comments of my PRU code for Machinekit: >>> >>> >>> https://github.com/machinekit/machinekit/blob/master/src/hal/drivers/hal_pru_generic/pru_generic.p#L135-L163 >>> >>> >>> -- >>> Charles Steinkuehler >>> [email protected] >>> >> -- 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.
