(circuit design) A digital logic circuit which can act either as a flip-flop or as a serial shift register and which is used to form a scan path.The most common design is a multiplexed flip-flop:___ ____ normal in --| || | |------|DQ|---- normal/scan output scan in ----|___/ mux || | || test mode ----++----|> | flip-flop | |____| clk ---------------+The addition of a multiplexor (mux) to each flip-flop' s input allows operation in either normal or test mode.The output of each flip-flop goes to the normal functional logic as well as to the scan input of the next multiplexor in the scan path.The other common design is level-sensitive scan design (LSSD).(1995-02-14)