Semiconductor integrated circuit device and method of design of semiconductor integrated circuit device

Abstract

A semiconductor integrated circuit device having a test clock generating circuit enabling a high performance test operation and a method of designing a semiconductor integrated circuit device enabling setting of high precision timing margins is disclosed. A test clock generating circuit having a register sequential circuit and a clock output control circuit is provided between a pulse generating circuit and a logic circuit. When a test operation is active, transfer of a clock pulse generated in the pulse generating circuit to the logic circuit is stopped and a test clock pulse operating the logic circuit is outputted using a pulse signal generated in the pulse generating circuit by controlling a clock transfer control circuit with the sequential circuit depending on setting information of a register. The test clock generating circuit is comprised using a logic design tool utilizing a computer in order to test logic circuit functions and timing margins.