Semiconductor device, receiver, transmitter, transceiver and communication system

摘要

A semiconductor device, includes a clock and data recovery unit to which a receive signal is inputted and which extracts, based on an operation clock signal, a clock signal and a data signal from the receive signal, a frequency error adjusting unit which generates a frequency error signal indicating a frequency error between the clock signal extracted from the receive signal and the operation clock signal, an operation clock generation unit which controls, based on the frequency error signal, a frequency of the operation clock signal, and a Spread Spectrum Clock Generator (SSCG) unit which varies the frequency of the operation clock signal by the SSCG unit based on the frequency error signal.

主权项

1. A semiconductor device, comprising:
a clock and data recovery unit to which a receive signal is inputted and which extracts, based on an operation clock signal, a clock signal and a data signal from the receive signal; a frequency error adjusting unit which generates a frequency error signal indicating a frequency error between the clock signal extracted from the receive signal and the operation clock signal; an operation clock generation unit which controls, based on the frequency error signal, a frequency of the operation clock signal; and a Spread Spectrum Clock Generator (SSCG) unit which varies the frequency of the operation clock signal by the SSCG unit based on the frequency error signal, wherein, when a difference between a maximum value of the frequency error signal and a minimum value of frequency error signal is equal to or smaller than a predetermined value, the SSCG unit spreads a spectrum of the operation clock signal generated by the operation clock generation unit based on an average value of frequency error signal and, when the difference between the maximum value and the minimum value is larger than the predetermined value, the SSCG unit does not spread the spectrum of the operation clock signal generated by the operation clock generation unit.