Why Scan Flip Flop?

A scan flip-flop is a D flip-flop with a 2x1 multiplexer added at its input D. ... Scan/Test Enable (SE/TE) is used to control the MUX i.e used as selection bit. Scan flip-flops are used extensively for device testing.

What is the purpose of scan chain?

Scan chain is a technique used in design for testing. The objective is to make testing easier by providing a simple way to set and observe every flip-flop in an IC. The basic structure of scan include the following set of signals in order to control and observe the scan mechanism.

Why do we need scan in DFT?

Scan testing is done in order to detect any manufacturing fault in the combinatorial logic block. In order to do so, the ATPG tool try to excite each and every node within the combinatorial logic block by applying input vectors at the flops of the scan chain.