PM Opc UNPACK
UNPACK = Unpack Nibbles
A = (8-Bits) Register A B = (8-Bits) Register B
; UNPACK B = A SHR 4 A = A AND 0x0F
Unpack byte in register A into 2 nibbles, storing them into register A and B.
Register A receive the lower nibble and register B receive the higher nibble.
; A = 0x21 UNPACK ; A = 0x01 ; B = 0x02