单片机的4个并行I/O端口是P0\P1\P2\P3,通常作为通用I/O端口使用,I/O的意思是输入/输出口。
查看答案
在输出数据时,必须外接上拉电阻的是P0 口。C51单片机的P3口的引脚,还具有外中断、串行通信等第二功能。
A. 对
B. 错
Nowlisten to the recording for a third time. Match each city to its problem.
Now listen to the recording for a third time. Match each city to its problem and a solution.
2、晶闸管对触发脉冲的要求是要有足够的_________、 触发脉冲前沿要陡幅值要________和 __________电压同步