A shift register is a sequential digital circuit that stores and moves data using flip-flops connected in a chain. A shared clock coordinates when the data moves. This lesson explains the basic structure and operation of shift registers and compares common input/output configurations.
A shift register is a cascade of flip-flops in which the output of one flip-flop connects to the input of the next. The flip-flops share a clock signal. On the active clock edge, each stage transfers its stored bit to the next stage, while a new bit may enter the first stage.
All flashcards
What is a shift register?
A sequential digital circuit made from flip-flops connected in a cascade, with a shared clock that advances stored data from one stage to the next.
What happens on a rising clock edge in a typical shift register?
Each stage takes the bit from the preceding stage, and a new input bit can enter the first stage. The data advances by one position.
How does SISO operation work?
Bits enter one at a time through a serial input, move through the flip-flop stages on clock edges, and leave one at a time through a serial output.
What is the difference between SIPO and PISO?
SIPO accepts bits serially and presents them in parallel. PISO loads a word in parallel and shifts its bits out serially.
What makes a universal shift register versatile?
It supports bidirectional shifting and provides both serial and parallel input/output capabilities.
Quiz questions
How are adjacent stages connected in a basic shift register?Answer: One flip-flop's output connects to the next flip-flop's input.
At what event does data move in the described edge-triggered shift register?Answer: At each rising edge of the shared clock.
Which configuration converts serial input into parallel outputs?Answer: Serial-in parallel-out (SIPO).
Why is a PIPO register not generally classified as a shift register?Answer: It transfers data in parallel without moving bits from stage to stage.
Why can serial connections help a microcontroller communicate with many binary devices?Answer: They can connect devices using fewer microcontroller pins.
Based on the Wikipedia article Shift register, licensed CC BY-SA 4.0. Adapted into a summary, flashcards and quizzes.