Forum Post: RE: can the PRU made to talk SPI without going through the host CPU?

Alexis,

[quote user="Alexis Martin"]What do you mean by "assuming it can keep up from a MIPS perspective" ?[/quote]As long as you are not trying to get the PRU to run more code than it can handle then there's no issue.

We don't have documentation discussing how to write a SPI driver on the PRU. There is a C compiler available in the CCSv6 App Center (note this is still a Beta product) which supports the full C/C++ language as well as the PRU Assembly instruction set. If C is your language of choice you can use this to write up your driver.

The PRU has access to the full memory map so it can access the SPI port directly via something as simple as a pointer. The only public information we have today on the PRU is covered in this github project, specifically the Reference Guide. Bear in mind that there are sections covering Assembly using the PASM utility which TI is not updating or supporting; however, it does cover the PRU hardware pretty well so this should be useful.

Additionally you can refer to the AM335x TRM for information on how the SPI port functions.