-class OpState:
- IDLE = 'IDLE' # no current instruction
- PRE1 = 'PRE1' # first prefix
- PRE2 = 'PRE2' # second prefix
- PREDIS = 'PREDIS' # pre-opcode displacement
- OPCODE = 'OPCODE' # opcode byte
- POSTDIS = 'POSTDIS' # post-opcode displacement
- IMM1 = 'IMM1' # first byte of immediate
- IMM2 = 'IMM2' # second byte of immediate
- ROP1 = 'ROP1' # first byte of read operand
- ROP2 = 'ROP2' # second byte of read operand
- WOP1 = 'WOP1' # first byte of write operand
- WOP2 = 'WOP2' # second byte of write operand
- RESTART = 'RESTART' # restart instruction decoding
-