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Self-Clocking SRAM Sequential Memory System

IP.com Disclosure Number: IPCOM000120979D
Original Publication Date: 1991-Jul-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 3 page(s) / 83K

Publishing Venue

IBM

Related People

Hennet, PP: AUTHOR [+4]

Abstract

Disclosed is circuitry to implement a self-clocking Static Random Access Memory (SRAM) system. The input strobes to the memory system are used to create an internal clock that is variable or follows the speed of the input data arrivals.

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This is the abbreviated version, containing approximately 82% of the total text.

Self-Clocking SRAM Sequential Memory System

      Disclosed is circuitry to implement a self-clocking
Static Random Access Memory (SRAM) system. The input strobes to the
memory system are used to create an internal clock that is variable
or follows the speed of the input data arrivals.

      Fig. 1 provides an organization of low-speed SRAM memory that
can be used to capture high-speed sequential data. By placing n
high-speed buffers (registers) in front of n slow-speed memory
systems, high- speed input data can be stored in the slow-speed
memory systems.  Fig.  1 assumes n is 16 and that the input data
arrives every 8 nanoseconds. Each memory group receives data every 8
X 16 = 128 nanoseconds. By using slow speed (assume 70 nanosecond
SRAM), the memory system is able to capture sequential data arriving
every 8 nanoseconds.

      The new and novel feature of this article is the ability to
internally generate a clock from the input strobes without using a
fixed clocking system.  A fixed clocking system is one that has a
constant interval of time between successive clock pulses.

      The self-clocking system is accomplished by making the input
strobe shift a shift register with one bit "on" to create an internal
clocking system that is variable with the input strobe signal. Figs.
2 and 3 depict how such a clocking system would function. The cycle n
clock pulses shown in Figs. 2 and 3 are at least twice the width of
the minimum input strobes, thereby pro...