Browse Prior Art Database

Clock Gating Circuit

IP.com Disclosure Number: IPCOM000079434D
Original Publication Date: 1973-Jul-01
Included in the Prior Art Database: 2005-Feb-26
Document File: 2 page(s) / 33K

Publishing Venue

IBM

Related People

Hansen, KM: AUTHOR [+3]

Abstract

This is a sequential logic circuit for controlling a number of logic clocks in a data processor. The functional requirements of the circuit are that clocks 5, 6 and 7 remain inactivated except when executing an instruction. In addition, it is required that each set of machine cycles must be initiated by a particular clock, in this case clock 5: and the cycles must stop after the CL 5 pulse.

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 100% of the total text.

Page 1 of 2

Clock Gating Circuit

This is a sequential logic circuit for controlling a number of logic clocks in a data processor. The functional requirements of the circuit are that clocks 5, 6 and 7 remain inactivated except when executing an instruction. In addition, it is required that each set of machine cycles must be initiated by a particular clock, in this case clock 5: and the cycles must stop after the CL 5 pulse.

In the figure the start and stop pulses occur immediately before and after the CL 5 pulse, respectively. The INITIATE pulse input into flip-flop 1 (FF1) sets the complement output. At the occurrence of the next START pulse, FF2 will be set, thus generating a first output to clock 5. This output sets FF3 through inverter 4, thereby setting gates 5 and 6 so that signals appear on the outputs of clock 6 and clock 7 upon the occurrence of inputs CL6 or CL7, respectively.

The clocks continue to function until a TERMINATE pulse is received on the reset line of FF1, thereby generating an output on the true line of FF1. At the occurrence of a STOP signal, FF2 and FF3 are reset, thereby suppressing the outputs on clocks 5, 6 and 7.

1

Page 2 of 2

2

[This page contains 2 pictures or other non-text objects]