A pulse is applied to each input of a 2-input NOR gate. One pulse goes HIGH at t=0 and goes back LOW at t=1ms. The other pulse goes HIGH at t=0.8ms and goes back LOW at t=3ms. The output pulse can be described as follows:一个两输入“或非”门的每个输入端都送入一个脉冲。其中一个脉冲在t=0ms时升为高电平,t=1ms时返回低电平;另外一个脉冲在t=0.8ms时升为高电平,t=3ms时返回低电平。则这个门电路的输出脉冲可以描述成:
A.
It goes LOW at t=0 and back HIGH at t=3ms. 该脉冲在 t=0ms 降为低电平, t=3ms 时返回高电平。
B.
It goes LOW at t=0.8ms and back HIGH at t=3ms. 该脉冲在 t=0.8ms 降为低电平, t=3ms 时返回高电平。
C.
It goes LOW at t=0.8ms and back HIGH at t=1ms. 该脉冲在 t=0.8ms 降为低电平, t=1ms 时返回高电平。
D.
It goes HIGH at t=0.8ms and back LOW at t=1ms. 该脉冲在 t=0.8ms 升为高电平, t=1ms 时返回低电平。