74HCT164 是 8 位边沿触发式移位寄存器，串行输入数据，然后并行输出。数据通过两个输入端（DSA 或 DSB）之一串行输入；任一输入端可以用作高电平使能端，控制另一输入端的数据输入。两个输入端或者连接在一起，或者把不用的输入端接高电平，一定不要悬空。-74HCT164 is an 8-bit edge triggered shift register, serial input data, and then output in parallel. Data input through two (DSA or DSB), one serial input　any input can be used to enable high-end, controlling the other input of data entry. Or to connect two inputs together, or to not have high input termination, must not be left vacant.