Definition
Shift Register
A shift register is a sequence of flip-flops that shifts stored bits by one position on each clock edge.
It can accept a serial input and produce a serial output, or convert a serial input into a parallel output.
Common forms include:
- Serial-in, serial-out: one bit enters and one bit leaves per clock edge.
- Serial-in, parallel-out: one bit enters per clock edge and the stored bits are available in parallel.
- Parallel-in, serial-out: several bits are loaded at once and then shifted out one by one.
- Parallel-in, parallel-out: bits are loaded and read in parallel while the register still supports shifting.
