Brandon,
Thanks for the response. I should have updated this thread when I learned from Alexander Haim
that muxing requires privilege. [1]
Unfortunately interrupt latency would have been too large for my use case, so I used external muxes instead. I posted a write up the beagleboard group. [2]
I was also pleased to learn other people found my work useful.
Matt Porter referenced my abx project in his presentation at the Embedded Linux Conference. [3] [4]
boxysean wrote a post about PRU usage that referenced this very thread. [5]
I think I even see vestiges of the code from this thread in Elias Bakken's replicape PRU code. [6] [7]
I love the power of the PRU and I love to see new applications. Sounds like you have something in the works.
Cheers,
Lyren
On Thursday, March 7, 2013 5:37:27 PM UTC-6,
brando...@gmail.com wrote:
Even though the PRU can access system memory, writes to the MUX settings require "privileged" (meaning kernel) access. So, no, it's not possible to change the mux from the PRU. But, you can use the PRU to trigger an interrupt, which can be handled by something in userspace (using UIO and the uio_pruss driver) or kernel space (with your own kernel driver) to change the pin mux, and then signal the PRU that the change has been made. Easiest way to signal the PRU would be a memory write to the pru data block that the pru would sit and poll.
On Monday, June 25, 2012 1:49:37 AM UTC-7, Lyren Brown wrote:Is it possible to alternate reads and writes from the PRU-ICSS to an external bidirectional bus?