General Description

The CD4021BC is an 8-stage parallel input/serial output

shift register. A parallel/serial control input enables individual

JAM inputs to each of 8 stages. Q outputs are available

from the sixth, seventh, and eighth stages. All outputs have

equal source and sink current capabilities and conform to

standard “B” series output drive.

When the parallel/serial control input is in the logical “0”

state, data is serially shifted into the register synchronously

with the positive transition of the clock. When the parallel/

serial control is in the logical “1” state, data is jammed into

each stage of the register asynchronously with the clock.