Integrated data jitter generator for the testing of high-speed serial interfaces

摘要

An integrated data jitter generator for the testing of high speed serial interfaces is provided. A transmit timing generator for use in a transmit data path includes a high frequency clock generator such as a phase-locked loop or a delay-locked loop having an input for receiving an oscillator or reference clock input. A clock modulator receives both an existing low frequency modulation signal and a high frequency modulation signal. A high-speed modulated clock signal is generated to enable jitter testing by a downstream-coupled receiver. Fixed frequencies such as 3, 6, 125, 150, 250, 300, 750, or 1500 MHz are used for the high-speed modulation signal, but any high-speed modulation frequency can be used to generate the desired amount of jitter. Likewise, the amplitude of the high frequency modulation signal can also be varied as desired.