Ah, thank you. These are excellent resources. I think I found the answer to my first question in the PRU Optimizing C/C++ Compiler v2.1 User Guide:
Section: 5.7.2 Global Register Variables The C/C++ compiler extends the C language by adding a special convention to > the register storage class specifier to allow the allocation of global > registers. This special global declaration has the form: register type > regid The regid parameter can be __R30 and __R31. The identifiers _ _R30 > and _ _R31 are each bound to their corresponding register R30 and R31, > respectively. These are control registers and should always be declared as > volatile. I am still a bit uncertain about the scratch pad. I have a value stored in a C variable, but how could I copy that value into inline assembler - so that I can write it to the scratch pad? On Tuesday, February 9, 2016 at 1:37:14 PM UTC+1, Soapy Smith wrote: > > There is a manual for the C compiler and the assembler: > > http://processors.wiki.ti.com/index.php/PRU-ICSS > > The links are on the right side of the page. > > Some of the PRU hardware specific registers are accessed via a large union > in a header file. It uses structs with "bit fields" so you can easily > access individual bits in the register. > Look for a header file called pru_cfg.h. But specifically to your > question, I'm still trying to figure out how the PRU input and output > registers R30 and R31 are done in C, as I > don't see those called out in the header file (in information overload at > this point!). > > Regarding the scratchpad, I believe it can't be accessed via C. However, > you can embed assembler codes into C source code. > If you go here: > > > https://training.ti.com/sitara-processors-building-blocks-for-pru-development-summary > > Download the firmware development slides and look at page 8. > > Regards, > Greg > > -- 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 beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
