Patent ID: 6765954
Filing Date: 2004-07-20
Classification: H04L

Abstract:
An analog front end for a digital subscriber line data communication system, comprising:a line driver for transmitting a data signal over a local loop; a digital to analog converter having an output connected to an input of the line driver, the digital to analog converter also having a data input for receiving a digital data signal and a clock input for receiving a clock signal; and a data signal supervisor circuit having a first input configured to receive the data signal and a second input configured to receive the clock signal, the supervisor circuit having comparison circuitry for logically comparing a first value of the data signal in relation to a signal change of the clock signal to a second value of the data signal in relation to a previous signal change of the clock signal and asserting a transmit control output signal if the first value of data signal is the same as the second value of the data signal.