Abstract: A method and circuit are provided for implementing switching factor reduction in Logic Built in Self Test (LBIST) diagnostics, and a design structure on which the subject circuit resides. Switching factor reduction logic is coupled to a Pseudo-Random Pattern Generator (PRPG) providing channel input patterns to a plurality of LBIST channels used for the LBIST diagnostics. The switching factor reduction logic selectively provides controlled channel input patterns for each of the plurality of channels.

Abstract: In a test data access system, a shift register is coupled the test data in pin. A first multiplexer is in data communication with the TDI pin and is configured to receive data from the TDI pin and to transmit data to each of the instruments. The first multiplexer is also configured to receive data from a data recirculation bit and to transmit data from the TDI pin to a plurality of instruments when the recirculation bit has a first value and to transmit data to the plurality of instruments from a recirculation line when the recirculation bit has a second value, different from the first value. A second multiplexer is configured to receive data from each of the plurality of instruments and is configured to transmit data from a selected one of the plurality of instruments, selected based on a value of data in the shift register. A first AND gate is configured to generate a gates clock to the shift register. A second AND gate is responsive to the first AND gate, configured to lock the shift register.

Abstract: A method and circuit are provided for implementing switching factor reduction in Logic Built in Self Test (LBIST) diagnostics, and a design structure on which the subject circuit resides. Switching factor reduction logic is coupled to a Pseudo-Random Pattern Generator (PRPG) providing channel input patterns to a plurality of LBIST channels used for the LBIST diagnostics. The switching factor reduction logic selectively provides controlled channel input patterns for each of the plurality of channels.