Waveform equalizer and shift register

摘要

In a tap 1 in a shift register of a waveform equalizer, data of an input signal is stored in a data storing FF 111 . A tap coefficient computing unit 114 calculates a tap coefficient, which is stored in a tap coefficient storing FF 112 and output to an absolute value computing unit 115 . The unit 115 obtains the absolute value of the tap coefficient. A comparator 116 compares the absolute value to a threshold value. A masking unit 117 masks and outputs the data from the data storing FF 111 to a multiplier 113 if the absolute value is smaller than the threshold value, while outputting the data from the data storing FF 111 without change if the absolute value is no less than the threshold value. The multiplier 113 multiplies the data of the input signal by the tap coefficient and outputs a signal to an adder 108.