Flip Flops

From TRCCompSci - AQA Computer Science
Revision as of 09:49, 23 March 2017 by Admin (talk | contribs)
Jump to: navigation, search

What is a flip flop

A flip-flop is used to store binary data, and is a simple latching circuit.

Basic (SR) Flip Flops

SR-Flip Flop

Basic flip flops are created using two NAND gates cross couples as seen in the image.

Problems with basic (SR) flip flops

D and T type Flip Flops

A flip flop has two inputs. One input is a control input. For a D flip flop, the control input is labelled D. For a T flip flop, the control input is labelled T. The other input is a clock input, labelled either with a triangle or CK. When a clock is drawn with a triangle like the ones below, these represent a positive-edge triggered clock, meaning that these can only change state when the clocks cycle is on a positive value i.e 1. When the clock is not on a positive value the bit stored within the flip flop is held i.e doesn't change.


D-FlipFlop.png Logic circuit for a D-Flip Flop 200px Logic circuit for a T-Flip Flop D type - Flip Flop

Edge triggered D Type Flip Flop