Research and implementation of clock recovery method based on software PLL

Jitter measurement is a critical element in the analysis and certification of serial data systems, which have no synchronous clock signals transmitted. A reference clock, therefore, must be recovered from the serial data signal under test. While clock recovery methods affect both the tracking ability as well as the total amount of jitter that can be measured. But traditional clock recovery methods have some drawbacks, which are dependent on different transmission protocols. In this paper, algorithms for signal clock recovery using software PLL, which calculate the rate of the serial data signal, can overcome the shortcomings of traditional methods. Besides, the design and implementation of clock recovery is given at the end of the paper. The design has been used in the high resolution oscilloscope and works well.