There are 4 I/O ports in 8051 MCU. In these ports, P0has No Pull-up register in it,P3has some special function pins, can be used as data bus.A.P0B.P1C.P2D.P3的答案是什么.用刷刷题APP,拍照搜索答疑.刷刷题(shuashuati.com)是专业的大学职业搜题找答案,刷题练习的