A signal processor used to process an analog read signal representing data stored on a magnetic disk allows for a faster read operation without requiring an increase in its circuit area or buffer memory space. The signal processor includes a decision feedback equalizer which selectively provides a feedback signal added to a read signal in reproducing data read from a storage medium. The signal processor also performs error correction. In performing error correction, the load of the error correcting process is detected and the processing speed is altered depending upon the detected load.
A semiconductor integrated circuit disclosed herein comprising: a phase control circuit which shifts a phase of a first clock signal based on a phase control signal and outputs a second clock signal; a first flip-flop to which one of the first clock signal and the second clock signal is inputted as a first operation clock signal, and which outputs evaluation data; a circuit under test which performs a predetermined process based on the evaluation data and outputs a result of the process as output data; and a second flip-flop to which the other of the first clock signal and the second clock signal is inputted as a second operation clock signal and the output data is inputted, and which outputs the output data inputted from the circuit under test.
A continuous-time domain Decision Feedback Equalizer (DFE) for use in a serial communication channel comprises in one embodiment a summer, a decision circuit, a capture flip-flop (FF) and an N-th order active filter. The DFE and its active filter operate in continuous time to give improved performance over a discrete-time DFE. In one embodiment involving a first-order active filter, the capture FF is outside the continuous-time negative feedback loop of the DFE and involves a differential signal amplifier. In another embodiment, the capture flip-flop is inside the DFE loop, and in a third embodiment the decision circuit comprises a comparator.
