Browse Prior Art Database

Detector for Missing Clock Pulse in Serial Waveform

IP.com Disclosure Number: IPCOM000065440D
Original Publication Date: 1985-Dec-01
Included in the Prior Art Database: 2005-Feb-19

Publishing Venue

IBM

Related People

Authors:
Fredericks, KJ Wiegand, MR [+details]

Abstract

In a serial data transmission system, a number of bits are transmitted as a serial frame that begins with a distinctive flag, such as several 0 bits followed by a 1 bit. In one system for encoding data in a serial waveform, each bit time has a clock window and a data window. In the data window, a signal transition represents a binary 0 and the absence of a transition represents a binary 1. A transition occurs in each clock window. In the detected waveform, a transition is converted to a down level and the absence of a transition is converted to an up level. Thus, the detector strips off the clock transitions. Fig. 1 shows the serial waveform and the detected serial data waveform with the columns for the clock and data windows headed C and D. A missing clock transition causes an anomalous up level in the data waveform. Fig.