(Or "Scan-In, Scan-Out") A electronic circuit design technique which aims to increase the controllability and observability of a digital logic circuit by incorporating special "Scan registers" into the circuit so that they form a Scan path. Some of the more common types of Scan design include the multiplexed register designs and {level-sensitive Scan design} (LSSD) used extensively by {IBM}. {Boundary Scan} can be used alone or in combination with either of the above techniques. ["Digital Systems Testing and Testable Design" by Abramovici, Breuer, and Friedman, ISBN 0-7167-8179-4]. ["Design of Testable Logic Circuits" by R.G. Bennetts, (Brunel/Southhampton Universities), ISBN 0-201-14403-4]. (1995-02-23)