9.36.3 PRU Machine Relocations

%pmem( expression )
Convert expression from byte-address to a word-address. In other words, shift right by two.
%label( expression )
Mark the given operand as a label. This is useful if you need to jump to a label that matches a register name.
          r1:
              jmp r1            ; Will jump to register R1
              jmp %label(r1)    ; Will jump to label r1