Browse Prior Art Database

Data/Clock Separation in a Double Frequency Recording System

IP.com Disclosure Number: IPCOM000094706D
Original Publication Date: 1965-May-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 2 page(s) / 32K

Publishing Venue

IBM

Related People

Thompson, JF: AUTHOR [+2]

Abstract

Separation of raw data into clock and data pulses is accomplished in a double frequency recording system. This is effected by creating a time reference window during each bit period for detecting any data pulses.

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Data/Clock Separation in a Double Frequency Recording System

Separation of raw data into clock and data pulses is accomplished in a double frequency recording system. This is effected by creating a time reference window during each bit period for detecting any data pulses.

The apparatus has input And 1 and a pair of And's 2 and 3 for providing the separated data and clock pulses, respectively. Latches 1 and 2 operate in response to the input raw data and delayed clock pulses to condition And's 2 and 3 and to establish the time reference window. A Separate latch is included in the system for controlling the initiation and termination of the separation process.

Prior to the initiation of the separation process, latch 1 is set in response to the off output of the Separate latch and latch 2 is set in response to the complement of raw data. When And 1 sets the Separate latch to initiate the process, it is assumed that the next pulse of the raw data is a clock pulse. Latches 1 and 2 and the Separate latch enable And 3 to permit the raw data to be supplied to And 3. A separated clock pulse is then provided by And 3.

The separated clock pulse is propagated through delay lines 1 a 2. The delay times of lines 1 and 2 are chosen so that delay 1 provides an output after the first pulse of raw data terminates, and delay 2 provides an output only after the rise of a possible data pulse.

The output of delay 1 resets latch 1. The output of delay 2 sets latch 1. Together these de...