Patent ID: 6195385
Filing Date: 2001-02-27
Classification: H04J,H04L,Y02D

Abstract:
A digital subscriber line (DSL) modem for receiving an incoming data stream and generating a sequence of data frames for a digital subscriber line, comprising:a clock source for providing a first clock signal having a first clock frequency;a modulation circuit adapted to receive said first clock signal;a framing circuit adapted to receive said first clock signal for providing a plurality of data frames to said modulation circuit, each of the plurality of data frames including at least one payload portion and at least one frame overhead portion, the framing circuit further providing a receiver overhead signal for indicating the insertion of frame overhead bits into each data frame;a clocking circuit adapted to receive said first clock signal and said receiver overhead signal for providing a second clock signal to said framing circuit, said clocking circuit including logic means for logically combining said first clock signal and said receiver overhead signal to generate said second clock signal, wherein said generated second clock signal has a specific timing relationship to said first clock signal and said receiver overhead signal such that while said receiver overhead signal is inactive, said second clock signal is active at a frequency substantially equal to said first clock frequency, and while said receiver overhead signal is active, said second clock signal is inactive; andwherein said framing circuit is adapted to utilize said second clock signal for communicating with said incoming data stream.