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Browse Prior Art Database

Clock Speed Doubler with Microprocessor Application

IP.com Disclosure Number: IPCOM000113103D
Original Publication Date: 1994-Jul-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 44K

Publishing Venue

IBM

Related People

Combs, JL: AUTHOR

Abstract

Disclosed is the use of an "exclusive or" (XOR) gate to provide an output clock signal at twice the frequency of an input clock signal.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 71% of the total text.

Clock Speed Doubler with Microprocessor Application

      Disclosed is the use of an "exclusive or" (XOR) gate to provide
an output clock signal at twice the frequency of an input clock
signal.

      As shown in the Figure, XOR gate 10 is provided with a first
input 12 driven by an input clock signal and a second input 14 driven
by the output line 16 through a network consisting of a resistor 18
and a grounded capacitor 20.

      The XOR gate 10 produces a low level output on line 16 when
both inputs 12 and 14 are low and when both these inputs are high;
otherwise gate 10 produces a high level output.  For example, between
pulses of the clock input signal applied to input 12, both inputs are
low, so the output line 16 is also held low.  However, when the rise
of the clock input signal occurs, input 12 becomes high, while input
14 remains low, so gate output line 16 is driven high.  As current
flows through resistor 18 and capacitor 20, input 14 is brought to a
high level.  At this point, both inputs are high, so output line 16
is driven low.  Next, the input clock signal falls, bringing input 12
to a low level.  The charge in capacitor 20 holds input 14 at a high
level, so output line 16 is again driven high.  As current flows
through resister 18, input 14 is again brought to a low level,
restoring the output on line 16 to a low level.

      Thus, each rise and each fall in the input clock signal is
followed by a pulse on output line 16.  The widt...