Browse Prior Art Database

Accessing Circuit for Memory Cell

IP.com Disclosure Number: IPCOM000076406D
Original Publication Date: 1972-Feb-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 33K

Publishing Venue

IBM

Related People

Bleher, JH: AUTHOR [+2]

Abstract

High-speed read/write access to any memory cell utilizing flip-flop devices is achieved with this circuit.

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 67% of the total text.

Page 1 of 2

Accessing Circuit for Memory Cell

High-speed read/write access to any memory cell utilizing flip-flop devices is achieved with this circuit.

A typical memory cell is formed of cross-coupled transistors 1, 2 connected through their respective collector circuits to current source 3. The collector circuits include load devices 4, 5 and current-limiting resistors 6, 7. Each transistor has a Schottky barrier diode 8, 9 connected in its collector-base circuit for antisaturation purposes. The emitters of the transistors are connected in common to word-select circuits 10.

The accessing circuit for each half of the memory cell consists of an emitter- follower 11, 12 and a Schottky barrier diode 13, 14. Connection of the accessing circuits is made to the collector circuit of one half of the memory cell, and through the cross coupling to the base of the other half of the memory cell. The circuits are connected for bidirectional operation of the memory cell to a single bit pair line. Thus, line 15 is coupled to emitter-follower 11 and diode 13 for controlling read/write operation of a binary "0", and line 16 is connected to emitter-follower 12 and diode 14 for read/write operation of a binary "1".

The emitter-follower in each of the access circuits is employed in the read operation and the Schottky barrier diode for the write operation. In the read operation, a positive word-select pulse is applied at 10. A potential difference is sensed between the two emitter-followers 11,...