SEMICONDUCTOR INTEGRATED CIRCUIT AND ITS DESIGN

摘要

PROBLEM TO BE SOLVED: To provide a semiconductor integrated circuit which can releaving simultaneous switching effects in a clock tree at the time of clock-switching operation, without degrading the performances of a synchronization circuit in the semiconductor integrated circuit to thereby increase its reliability, and a method for designing the semiconductor integrated circuit. SOLUTION: A synchronization circuit in a semiconductor integrated circuit includes registers D1, D2 and D3, to which clocks are supplied from clock buffers B0, B1, B2 and B3 forming a clock tree, and random logics C1, C2 and C3 for data transfer between the registers. Delay elements A1 and A2 for providing such delays within a range as to ensure holding of the registers are inserted between the clock buffers.