Programmable glitch filter for an asynchronous data communication interface

摘要

An apparatus and a method for filtering glitches in a data communications controller receiving asynchronous input data signals varying between two signal levels representing two bit values and having a predetermined input bit period, and sending output data signals corresponding to the input data signals. Glitches are detected in the input data signals by detecting reversals of signal level having a duration less than the input bit period. A glitch time value corresponding to the glitch duration is determined, and then a sampling clock rate is set at a rate determined from the glitch time value. The input data signals are sampled at the sampling clock rate to generate a sequence of input data samples. A voting number of input data samples are monitored and an output signal is provided, representing the value of a majority of the sequential input data samples.