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Browse Prior Art Database

Analog Read Only Storage

IP.com Disclosure Number: IPCOM000090359D
Original Publication Date: 1969-Apr-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 39K

Publishing Venue

IBM

Related People

Shutler, WF: AUTHOR

Abstract

An analog signal can be generated from a capacitive read-only storage by sequentially driving bit lines of the storage in a proper sequence to obtain the desired function. The storage members of a capacitive read-only memory are essentially RC differentiating circuits. Thus, signals can be applied to the drive lines of the memory in a predetermined sequence to obtain a step approximation of an analog signal on the sense lines of the memory.

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Analog Read Only Storage

An analog signal can be generated from a capacitive read-only storage by sequentially driving bit lines of the storage in a proper sequence to obtain the desired function. The storage members of a capacitive read-only memory are essentially RC differentiating circuits. Thus, signals can be applied to the drive lines of the memory in a predetermined sequence to obtain a step approximation of an analog signal on the sense lines of the memory.

Each storage member, drawing A, consists of a pair of capacitors located at the intersection of each pair of drive and balance lines 10 and 12 with the sense lines 14 and 16. This allows three basic information patterns to exist at the different drive-sense intersections. A + pattern exists at the intersection of drive and balance lines D2 and B2 with the sense lines SO. A - pattern exists at the intersection of drive and balance lines D1 and B1 with the sense line S0. A 0 pattern exists at the intersection of drive and balance lines D0 and B0 with the sense lines S0. By using combinations of these patterns along a sense line, an analog signal is generated at the output of the differential sense amplifier.

As an example, assume it is desired to obtain the waveform shown in drawing B. Then by using a ramp function as the drive waveform and turning on the drivers D0 to D5 in the sequence shown in drawing C, the desired waveform is produced at E0. By selecting the number of drivers and their turnon interv...