On 8/28/2017 3:38 AM, Babak akbari wrote: > I'm an absolute beginner in the field of pru. I was wondering what actually > takes place when a bin file is loaded into the instruction memory of a pru. I > looked through the prussdrv.c in am335x_pru_package file where application > loader api functions are located. > https://github.com/beagleboard/am335x_pru_package/blob/master/pru_sw/app_loader/interface/prussdrv.c > > My question is in > int prussdrv_pru_write_memory (unsigned int pru_ram_id, unsigned int > wordoffset, unsigned int *memarea, unsigned int bytelength); > function scope > > > wordlength = (bytelength + 3) >> 2; //Adjust length as multiple of 4 bytes > > for (i = 0; i < wordlength; i++) { > *(pruramarea + i + wordoffset) = *(memarea + i); > } > return wordlength; > > why wordoffset is added to pruramarea which holds the the address of the > instruction memory.but according to this guide > > http://processors.wiki.ti.com/index.php/PRU_Linux_Application_Loader_API_Guide > > wordoffset is the offset from *memarea and I think wordoffset is to be added > to memarea instead , otherwise we are missing some parts of the instruction > memory.
It looks like the documentation is unclear (or wrong). The offset is the offset into the mapped memory region (pruramarea, selected by what you pass as the pru_ram_id parameter) where the memory buffer specified by memarea & bytelength will be copied. When in doubt, trust the code! :) > My other question is why pru instruction memory is said to be 8kB But > according to the trm pru global memory section the instruction memory is just > 4k Which TRM? The TRMs I have for the AM335x refer to 8KB instruction memory for each PRU core, but there are several versions of the PRU floating around in different SoC's. -- Charles Steinkuehler char...@steinkuehler.net -- 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. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/bc13310e-4c4d-460c-357c-65178c5447bc%40steinkuehler.net. For more options, visit https://groups.google.com/d/optout.
