PROCESSOR-SDK-AM62X: how to access DDR memory from PRUSS-M

Hello Martin,

PRU is able to read pretty much any area of memory space, and it can write any memory space that does not require elevated permissions (e.g., PRU can read the pinmux setting registers, but it cannot write to them). You should not need to use the RAT to access DDR unless your DDR is at a 64 bit address instead of a 32 bit address (I.e., larger than 4GB, i.e., above 0xFFFF_FFFF).

There is one difference between AM335x and AM62x in terms of memory access: in AM335x/AM437x PRU-ICSS, the PRU's OCP port must be enabled before the PRU core can access memory external to the PRU-ICSS. In AM62x PRUSS, the PRU does not need to enable any specific register bits before it can read/write to a memory location external to the PRUSS.

Regards,

Nick