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Browse Prior Art Database

Deskewing Using Last Bit of a Byte

IP.com Disclosure Number: IPCOM000097475D
Original Publication Date: 1962-Dec-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 58K

Publishing Venue

IBM

Related People

Miller, EW: AUTHOR

Abstract

While reading a byte, i. e., a group of bits intended to be read simultaneously from parallel tracks on tape or from a data transmission channel, the triggers of the receiving register are set at a different time because of skew. This skew accommodation circuit is to line up, timewise, the bits of a byte.

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Deskewing Using Last Bit of a Byte

While reading a byte, i. e., a group of bits intended to be read simultaneously from parallel tracks on tape or from a data transmission channel, the triggers of the receiving register are set at a different time because of skew. This skew accommodation circuit is to line up, timewise, the bits of a byte.

The left drawing shows that each tape track T1... T4 has a pair of triggers, T1A-T1B, T2A-T2B, T3A-T3B, T4A-T4B, respectively, for receiving information from the tape. Both triggers of each pair are in the reset condition if no bit has been read from the associated track. For a 1 bit, trigger T1A is set and for a 0 bit, T1B is set. An Or 01... 04, provided for each trigger pair, indicates when a bit is read from its track and delivers its output to And 45. All inputs of And 45 are conditioned only after the last bit of a byte has been read. As soon as 45 is activated, its output samples the outputs of T1B... T4B by means of gates 56...
59. The data is read out simultaneously and in parallel. After the delay 46, all triggers T1A... T4B are reset.

In the right drawing, each of the triggers T1... T4 is set only by the 1 bit in its associated tracks, so that this circuit can be used with pure binary recording. The circuitry includes clocks C1... C4 for each track to recognize the time position of each bit. The clocks can be phase-locked oscillators, synchronized by the one bits of the tracks, so that the triggers T5... T8 are set a...