Additional bytes may be required to specify 8-bit or 16-bit offsets. The full instruction is then:
| Op-code | Post-byte | Offset (if required) | Offset (if required) |
Type Forms Assembler Postbyte + + Form Opcode ~ #
Constant Offset from R No Offset ,R 1RR00100 0 0 (2's complement Offsets) 5-bit Offset n,R 0RRnnnnn 1 0 8-bit Offset n,R 1RR01000 1 1 16-bit Offset n,R 1RR01001 4 2 Accumulator Offset From R A Register Offset A,R 1RR00110 1 0 (2's complement Offsets) B Register Offset B,R 1RR00101 1 0 D Register Offset D,R 1RR01011 4 0 Auto Increment/Decrement R Increment by 1 ,R+ 1RR00000 2 0 Increment by 2 ,R++ 1RR00001 3 0 Decrement by 1 ,-R 1RR00010 2 0 Decrement by 2 ,--R 1RR00011 3 0 Constant Offset from PC 8-bit Offset n,PCR 1xx01100 1 1 (2's complement Offsets) 16-bit Offset n,PCR 1xx01101 5 2
R=X,Y,U or S xx=don't care +~ - additional clock cycles following op-code RR: +# - additional bytes after postbyte 00 = X 01 = Y 10 = U 11 = S