Browse Prior Art Database

Programmable Clock Signal Generator

IP.com Disclosure Number: IPCOM000112973D
Original Publication Date: 1994-Jun-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 60K

Publishing Venue

IBM

Related People

Nguyen, LD: AUTHOR

Abstract

Disclosed is circuit for generating a desired frequency from the higher frequency of a system clock. A counter, running at the frequency of the system clock, generates a signal addressing a memory register, the output of which is used to gate the system clock signal according to data stored in the register.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 56% of the total text.

Programmable Clock Signal Generator

      Disclosed is circuit for generating a desired frequency from
the higher frequency of a system clock.  A counter, running at the
frequency of the system clock, generates a signal addressing a memory
register, the output of which is used to gate the system clock signal
according to data stored in the register.

      A block diagram of the circuit is shown in Fig. 1.  The system
clock signal, SYS CLOCK, is applied as an input to a counter 10,
which is a ring counter beginning a count from zero after each time a
full count is reached.  The output of counter 10 is used to address a
memory register 12, having a number of locations equal to the maximum
count of counter 10 and storing one bit per location.

      The number to which counter 10 counts before resetting (the
full count value) is set according to an input loaded into the
counter during system setup.  The value stored in memory register 12
is also set during system setup, as MEM DATA IN.  In this way,
control over the critical parameters of the circuit is exerted by
software.

      In the run mode, counter 10 counts system clock pulses,
providing an output, COUNTER OUTPUT, representing the value of the
count.  This output is provided through a selection circuit 14 to
address the data stored in memory register 12.  The output signal of
memory register 12, MEM DATA OUT, which is at a "zero" or "one"
level, depending on the data stored at the location being...