Patent ID: 7259598
Filing Date: 2007-08-21
Classification: G06F

Abstract:
1. A clock switching circuit, switching an output clock from an original clock signal to a new clock signal, and comprising: a clock generator, receiving two different clock signals, and according to a switch signal, generating a first reference clock signal, which is congruous to said original clock signal; an enable-signal generator, coupled to said clock generator, and receiving said first reference clock signal; and an output-clock generator, coupled to said clock generator and said enable-signal generator, and receiving said first reference clock signal, and a logic gate coupled to said enable-signal generator and said output-clock generator, wherein according to a respective negative edge of said original clock signal, said enable-signal generator turns off said logic gate; according to said first reference clock signal, said output-clock generator creates a second reference clock signal which is congruous to said new clock signal; next, said output-clock generator sends said second reference clock signal to said enable-signal generator; according to the negative edge of said second reference clock signal, said logic gate is turned on, and said new clock signal created by said output-clock generator is output from said logic gate.