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Counter With Simultaneous Carry

IP.com Disclosure Number: IPCOM000097930D
Original Publication Date: 1961-Oct-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 51K

Publishing Venue

IBM

Related People

Carroll, WN: AUTHOR [+2]

Abstract

The binary counter is comprised of a number of triggers, 10, 12, 14, 16, 18, in which binary numbers are registered in true form, if odd, and in complement form, if even. The bit corresponding to the 0 stage is not used. It must always be equal to 1 for odd numbers as well as for even ones.

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Counter With Simultaneous Carry

The binary counter is comprised of a number of triggers, 10, 12, 14, 16, 18, in which binary numbers are registered in true form, if odd, and in complement form, if even.

The bit corresponding to the 0 stage is not used. It must always be equal to 1 for odd numbers as well as for even ones.

Input trigger 44 is ON for odd numbers and OFF for even numbers. As regards odd numbers, 44 conditions AND's 56, 58, 60, 62 and 64. The trigger output signal thus comes from the left hand outputs of the triggers and is in true form. As to even numbers, 44 conditions AND's 66, 68, 70, 72 and 74. It is, thus, the complement of the number stored in the triggers which appears on the output terminals 25, 24, 23, 22 and 21. In this way, at these terminals, the result derived from the counter is always in true form.

Counting pulses are applied to terminal 50. If trigger 44 is OFF, the pulse switches it ON, and conversely.

In order to go from an even number to the next one, the input pulse flows through AND 48 and complements all triggers.

To go from an odd number to the next one, the input pulse flows through AND 46 and then conditions one input of logical circuits 26, 28, 30, 32 and 34. From the first stage, whose associated trigger is OFF, this input pulse flows through OR circuits such as 36, 38, 40 or 42, and thus complements all triggers above the least significant 0.

The advantages are: 1. Counting is speeded up. All complement operations are per...