74180: Parity Generator/Tester

This is a special-purpose TTL device that will indicate whether the number of 1's on the inputs is even or odd. It is used as an error tester in computer systems or as a "single note" detector in electronic music.

The inputs to be tested are applied to A through H. Unused inputs are terminated either to ground or high, as needed.

If the Even input is made high and the Odd input is made low, an even number of input 1's drive the Σ Even output high and the Σ Odd output low. An odd number of 1's drives the Σ Even output low and the Σ Odd output high.

If both Even and Odd inputs are high, both outputs will go low, regardless of the A-through-H inputs. If both Even and Odd inputs are low, both outputs will go high, regardless of the A-through-H inputs.

If the Even input is made low and the Odd input is made high, an even number of input 1's drive the Σ Even output low and the Σ Odd output high. An odd number of 1's drive the Σ Even output high and the Σ Odd output low.

Pinout
Pin # Pin Assignment
1 Input G
2 Input H
3 Even Input
4 Odd Input
5 Σ Even
6 Σ Odd
7 Ground
8 Input A
9 Input B
10 Input C
11 Input D
12 Input E
13 Input F
14 Power (+5V)

Contents