A scan flip-flop (SFF) is a muxed input master-slave based D flip-flop. In other words, a scan flip-flop is a D flip-flop that allows its input to come from an alternative source.

Overview

A scan flip-flop is a D flip-flop with a multiplexer added at the input with one input of the MUX acting as the functional input D, with the other input serving as the Scan-In (SI) input. Scan/Test Enable (SE/TE) is used to control the MUX selection bit. Scan flip-flops are used extensively for device testing.

See also

• Boundary scan
• Scan chain
• JTAG