【单选题】
37若要让Timer作为外部计数只用,应如何设置?___
A. Gate=0
B. Gate=1
C. C/=0
D. C/=1
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答案
D
解析
暂无解析
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39下列哪个不是8×51所提供的省电方式?___
A. PD方式
B. IDL方式
C. LP方式
D. 待机方式
【单选题】
89S51的看门狗有何作用?___
A. 重复执行程序
B. 找回遗失数据
C. 复位系统
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41若要启用WDT,则应依次填入WDTRST寄存器哪些数据?___
A. 0xe1、0xe2
B. 0xe1、0x1e
C. 0x1e、0xe1
D. 0x10、0x01
【单选题】
8×51的定时器,在下列哪种方式下具有自动加载功能?___
A. Mode0
B. Mode1
C. Mode2
D. Mode3
【单选题】
45下列哪种AD转换器的转换速度比较快?___
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46下列哪种AD转换器的精密度比较高?___
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47对于8×8 LED点阵而言,其中的LED个数及引脚各为多少?___
A. 64、16
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【单选题】
48在共阳极型8×8 LED点阵里,其阳极如何连接?___
A. 各行阳极连接到行引脚
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D. 各列阳极连接到行引脚
【单选题】
49在共阳极型8×8 LED点阵里,其阴极如何连接?___
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【单选题】
50双色8×8 LED点阵的列引脚与行引脚各位多少?___
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___的方向规定由高电位点指向低电位点。
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三相电动势到达最大的顺序是不同的,这种达到最大值的先后次序,称三相电源的相序,相序为U-V-W-U,称为___。
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___反映了在不含电源的一段电路中,电流与这段电路两端的电压及电阻的关系。
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并联电路中的总电流等于各电阻中的___。
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串联电路中流过每个电阻的电流都___。
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___的电阻首尾依次相连,中间无分支的联结方式叫电阻的串联。
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