【单选题】【消耗次数:1】
单片机8051的XTAL1和XTAL2引脚是引脚。
外接定时器
外接串行口
外接中断
外接晶振
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相关题目
【单选题】 单片机8051的XTAL1和XTAL2引脚是____引脚。
①  外接晶振
②  外接串行口
③  外接中断
④  外接定时器
【单选题】 当8051单片机外接时钟信号时,应从(  )脚接入。
①  T0
②  XTAL2
③  XTAL1
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【单选题】 8051单片机的VSS(20)引脚是____引脚。
①  主电源+5V
②  接地
③  备用电源
④  访问片外存贮器
【单选题】 8051单片机的VCC(40)引脚是____引脚。
①  主电源+5V
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【单选题】 8051单片机的VCC(40)引脚是引脚。
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【单选题】 单片机8051的ALE引脚是 。
①  输出高电平
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③  输出低电平
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③  输入定时器1的计数脉冲
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【单选题】 51单片机的( )口的引脚,还具有外中断、串行通信等第二功能
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【单选题】 单片机8051的/EA引脚 。
①  必须接地
②  必须接+5V
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【单选题】 80C51单片机的( )口的引脚,还具有外中断、串行通信等第二功能。
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随机题目
【单选题】 23. Anna was reading a piece of science fiction, completely ____ to the outside world.
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【单选题】 Mike is always losing something. He is a ____boy.
①  careful
②  hopeful
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【单选题】 Dont be too ____ about things youre not supposed to know.
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②  amusing
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【单选题】 You can take as many as you like because these handouts are free of ____.
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【单选题】 22. One day while Mr. King was working, he had a/an ____: his left leg was badly injured.
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②  B. zone ?
③  uniform ?
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①  fun
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【单选题】 Im going to the supermarket this afternoon. Do you have anything ____?
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①  to have closed
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