【单选题】【消耗次数:1】
MCS-51单片机的4个并行I/O口作为通用I/O口使用,在输出数据时,必须外接上拉电阻的是____。
P0口
P1口
P2口
P3口
参考答案:
复制
纠错
相关题目
【判断题】 8051单片机的P2口只能用作通用I/O口
①  正确
②  错误
【单选题】 MCS-51单片机的P1口的功能是。
①  可作通用双向I/O口用
②  可作一般I/O口用
③  可作地址/数据总线用
④  可作通用I/O口用
【单选题】 ( )作为通用I/O口时,要外接上拉电阻
①  P0
②  P1
③  P2
④  P3
【单选题】 单片机的P0、P1口作输入用途之前必须 ____。
①  在相应端口先置1
②  在相应端口先置0
③  外接高电平
④  外接上拉电阻
【单选题】 单片机的P0、P1口作输入用途之前必须。
①  在相应端口先置1
②  在相应端口先置0
③  外接高电平
④  外接上拉电阻
【判断题】 8051单片机的I/O口中,P1口具有第二功能。
①  正确
②  错误
【单选题】 当把8051单片机的8位并行I/O接口P1作为数据输入接口使用时,必须先向P1口的锁存器输出数据。
①  0
②  1
③  255
④  256
【判断题】 51单片机的P0口既可以做数据口线又可以做为地址口线
①  正确
②  错误
【判断题】 P2口既可以作为I/O使用,又可以作地址/数据复用口使用。
①  正确
②  错误
【单选题】 8051单片机的P0口驱动拉电流负载时必须接____。
①  电源
② 
③  下拉电阻
④  上拉电阻
随机题目
【单选题】 With the old man____ the way, we had no trouble in finding that mysterious cave.
①  lead
②  to be led
③  leading
④  led
【单选题】 The computer of this kind is ____ handling with all kinds of information.
①  capable to
②  able to
③  capable of
④  able of
【单选题】 People ____ to the speech in different ways: some got angry while others nodded in agreement.
①  responded
②  acted
③  answered
④  replied
【单选题】 23. Anna was reading a piece of science fiction, completely ____ to the outside world.
①  being
②  having lost
③  losing
④  lost
【单选题】 Mike is always losing something. He is a ____boy.
①  careful
②  hopeful
③  careless
④  hopeless
【单选题】 Dont be too ____ about things youre not supposed to know.
①  strange
②  amusing
③  curious
④  conscious
【单选题】 You can take as many as you like because these handouts are free of ____.
①  fare
②  charge
③  money
④  pay
【单选题】 22. One day while Mr. King was working, he had a/an ____: his left leg was badly injured.
①  business
②  accident
③  matter
④  event
【单选题】 This is the military ____, and nobody is allowed to get in without permission. ?
①  bond ?
②  B. zone ?
③  uniform ?
④  zoo ?
【单选题】 I haven’t made any new friends yet and everybody here makes ____ of me.
①  fun
②  smile
③  laugh
④  joy