Direct PRU -> R30
In this test we use the direct register R30 in order to estimate the performance.
TIME/DIV 0,02 µs, GPIO performance ~65 MHz
TOP: SET r30.t3 CLR r30.t3 jmp TOP
TIME/DIV 0,02 µs, GPIO performance 50 MHz
After this test, the program was changed:
LEDON: SET r30.t3 jmp LEDOFF LEDOFF: CLR r30.t3 jmp LEDON
The GPIO performance was exactly 50 MHz (200 MHz / 4 instructions).