BI-DIRECTIONAL SCAN FLIP-FLOP CIRCUIT AND METHOD

A scan flip-flop circuit includes a selection circuit including first and second input terminals coupled to first and second I/O nodes, a flip-flop circuit coupled to the selection circuit, a first driver coupled between the flip-flop circuit and the first I/O node, and a second driver coupled between the flip-flop circuit and the second I/O node. The selection circuit and drivers receive a scan direction signal. In response to a first logic level of the scan direction signal, the selection circuit responds to a first signal received at the first input terminal, and the second driver outputs a second signal responsive to a flip-flop circuit output signal. In response to a second logic level of the scan direction signal, the selection circuit responds to a third signal received at the second input terminal, and the first driver outputs a fourth signal responsive to the flip-flop circuit output signal.