Patent ID: 7613971
Filing Date: 2009-11-03
Classification: G01R

Abstract:
1. A semiconductor integrated circuit comprising: a first input side flip-flop; a first combinational circuit having an input connected with said first input side flip-flop; an output side flip-flop connected with an output of said first combinational circuit; a second input side flip-flop; a second combinational circuit having an input connected with said second input side flip-flop and an output connected with said first input side flip-flop; and a delay test circuit, wherein said delay test circuit generates output clock pulses by removing an optional one from equal to or more than 3 continuing clock pulses of an input clock signal, and supplies said output clock pulses to said first input side flip-flop, said output side flip-flop and said second input side flip-flop; wherein: said first combinational circuit is a multi-cycle path and receives a first input data from said first input side flip-flop to output a first output data indicating an operation result of said first input data to said output side flip-flop; said second combinational circuit is a single-cycle path and receives a second input data from said second input side flip-flop to output a second output data indicating an operation result of said second input data to said first input side flip-flop; said first input side flip-flop and said second input side flip-flop output said first input data and said second input data to said first and second combinational circuits, respectively, in response to an edge of a first one of said output clock pulses; said output side flip-flop and said first input side flip-flop simultaneously receive said first output data and said second output data therefrom, respectively, in response to an edge of a second one of said output clock pulses; and a time interval between said edge of said first one of output clock pulses and said edge of said second one of output clock pulses corresponds to a first combinational circuit data transfer.