| 摘要 |
An apparatus that includes a module for controlling the frequency of a voltage controlled oscillator (VCO) as part of a phase locked loop (PLL), or clock and data recovery (CDR) when an input reference signal to the PLL or serial data to the CDR has ceased from being received. In particular, the apparatus comprises a VCO adapted to generate a VCO clock signal, a first control module adapted to control the frequency of the VCO clock signal based on the input reference signal, and a second control module adapted to control the frequency of the VCO clock signal in response to an absence of the input reference signal. By controlling the frequency of the VCO clock signal during an absence of the input reference signal, the first control module is able to more easily re-acquire control the frequency of the VCO clock signal when the input reference signal is received again. |
