74165: Shift Register, 8 Bits (Parallel Input, Serial Output)

This is an eight-stage shift-right-only shift register. It may be used as a serial-in/serial-out or parallel-in/serial-out register.

For normal operation, the Enable is held low and the Load is held high. Every negative-to-positive clock transition (positive edge) shifts the data one stage to the right.

For instance, the data on the Serial input goes into A. A goes to B. B goes to C, C goes to D. D goes to E. E goes to F. F goes to G. G goes to H. H goes to the next stage or is lost. The complement of the eighth stage is also available and provides inverted data.

To parallel-load the register, the Load input is briefly brought to ground while applying the desired input word to the parallel inputs A through H.

Shifting may be inhibited by bringing the Enable input high.

The clock must be bounceless and noise free, producing one, and only one, positive transition per desired shift.

Pinout
Pin # Pin Assignment
1 Load
2 Clock
3 Input E
4 Input F
5 Input G
6 Input H
7 Output (complement)
8 Ground
9 Output
10 Serial in
11 Input A
12 Input B
13 Input C
14 Input D
15 Enable
16 Power (+5V)

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