說明下列指令中不合法的原因。 (1)MOV 64H, CL (2)MOV CL, 100H (3)MOV CL, 256 (4)MOV SS, 6180H (5)MOV CS, WORD PTR[BX] (6)MOV DS, SS (7)XCHG AL, 40H (8)XCHG ES, AX (9)IN 160H, AL (10)CMP [SI], [BX] (11)MOV DS, 1000H (12)POP CS