CLOCK SWITCH DEVICE AND SYSTEM-ON-CHIP HAVING THE SAME

摘要

A clock switch device comprises a control unit and a switching circuit. The control unit sets a clock switching section by using a control signal when logic levels of all signals are changed. The switching circuit receives a first clock signal, a second clock signal, and an auxiliary clock signal, outputs, as a glitch free clock signal, any one clock signal from the first and second clock signals before the clock switching section on the basis of the control signal, stops an output of any one clock signal during the clock switching section to output the auxiliary clock signal as the glitch free clock signal, and stops an output of the auxiliary clock signal after the clock switching section to output the other clock signal of the first and second clock signals as the glitch free clock signal.