Series interface circuit for discrete logic input connecting pin of electronic system, uses bit value sorting circuit to provide first logic value when counter state is above reset value

摘要

A serial interfacing circuit comprising a decoder (24) for converting a PWM input signal into a sequence of low and high logic values, a flank detection circuit (26) for detecting the falling and rising flanks of the input signal and a bit value sorting circuit (28) which supplies a first logic value when the counter state of an up/down counter (30) during detection of a signal flank in the first direction is above the reset value and a second logic value when the counter state of the up/down counter (30) during detection of a signal flank in the first direction is equal to/or less than the reset value .