In computing or digital,nibble means combination of 4-bit e.g. 0010 or 0001 etc.
As shown in above circuit, there are two input nibble one on the left is A3A2A1Ao and on the right is B3B2B1Bo. The control signal SELECT determines which input nibble(A3A2A1A or B3B2B1Bo) is transmitted to the output.
When SELECT is low, the four NAND gates on the left are activated, so output is Y3Y2Y1Yo=A3A2A1Ao
When SELECT is high, the four NAND gates on the right are activated and we get Y3Y2Y1Yo=B3B2B1Bo
- Pinout diagram of Nibble Multiplexer IC-74157