Synchronizing circuit with dynamic and static latch circuitry

Abstract

A synchronizing circuit including a plurality of latches, comprised of a first dynamic type through latch circuit and a second dynamic type through latch circuit between which is disposed a static type through latch circuit, the circuits connected in cascade. Data is sampled at the timing of the rising edge of the clock signal generated by a pulse generation circuit connected to a clock input circuit and data is output at the timing of the trailing edge. By defining the clock pulse width generated at the pulse generation circuit larger than the clock skew, it is possible to prevent malfunctions of the LSI caused by clock skew caused by deviation of timing of the clock distribution. Moreover, by providing a dynamic type through circuit for a scan test input to the first dynamic type through latch circuit in parallel, a scanning function can be realized and a malfunction due to the clock skew during scanning can be prevented.