Browse Prior Art Database

Data Block Scrambler and Unscrambler

IP.com Disclosure Number: IPCOM000078572D
Original Publication Date: 1973-Jan-01
Included in the Prior Art Database: 2005-Feb-26
Document File: 8 page(s) / 173K

Publishing Venue

IBM

Related People

Roth, RI: AUTHOR

Abstract

This description relates to apparatus for scrambling and unscrambling blocks of data.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 18% of the total text.

Page 1 of 8

Data Block Scrambler and Unscrambler

This description relates to apparatus for scrambling and unscrambling blocks of data.

Reference should be made to Figs. 1A,, 1B, 1C, 1D, and 1E. When these sheets are fastened together, as shown in Fig. 1, they make up the wiring diagram of the embodiment. On Fig. 1A, there are eight flip-flops numbered 130 through 144, inclusive. These flip-flops can operate as independent modulo 2 counters or they can be connected in groups to form several counters. For example, there could be several modulo 2 counters and a few modulo 4 counters. Other combinations of modulo 2, modulo 4, modulo 8, modulo 16, and so forth, up to a single counter of modulo 256 could be arranged for. It is believed that a preferred arrangement would be several counters of probably modulo 2, modulo 4, modulo 8, or modulo 16. The AND circuits 146 through 160, inclusive, are provided so that these flip-flops can be connected up in groups.

The just mentioned AND circuits provide for the propagation of carries between flip-flops of each group. The AND circuits 162 through 176, inclusive, are provided in order to properly increment the counters. The AND circuits just described are enabled by the wires labelled A-0 through A-7. These wires are the outputs of the decoder 180 in Fig. 1C This decoder 180 decodes the contents of the counter A, which is a modulo 8 counter. In order to produce an operating device, it was necessary t connect up the flip-flops 130 through 144, inclusive, in some manner in order to illustrate the operation of the machine. The manner in which these are connected on Fig. 1 will be described. However, it should be emphasized that this is only one possible arrangement of these flip-flops and that many other arrangements could be made.

When wire A-0 is active, all the flip-flops 130 through 144 operate as modulo 2 counters.

When wire A-1 is active, flip-flops 130 and 132 are connected up as a modulo 4 counter. Flip-flops 134, 136, 138, and 140 are modulo 2 counters and flip-flops 142 and 144 comprise a modulo 4 counter. When wire A-2 is active, flip-flops 130 and 132 are connected and form a modulo 4 counter. Flip-flops 134 and 136 are connected to form another modulo 4 counter. Flip-flops 138, 140, 142 and 144 are modulo 2 counters.

When wire A-3 is active, flip-flops 130, 132, 134, and 136 are modulo 2 counters. Flip-flops 138 and 140 comprise a modulo 4 counter and flip-flops 142 and 144 comprise another modulo 4 counter.

When wire A-4 is active, flip-flops 130, 144, and 142 comprise a modulo 8 counter. Flip-flops 132, 134, and 136 are modulo 2 counters. Flip-flops 138 and 140 comprise a modulo 4 counter.

When wire A-5 is active, flip-flops 130, 132, and 134 comprise a modulo 8 counter. Flip-flops 136, 138, 140, 142 and 144 are modulo 2 counters.

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When wire A-6 is active, flip-flops 130, 132 and 144 are modulo 2 counters. Flip-flops 134, 136 and 138 comprise a modulo 8 counter and flip-flops 140 and...