Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

Static Memory Composed of Compatible RAM/ROS Cells

IP.com Disclosure Number: IPCOM000036012D
Original Publication Date: 1989-Aug-01
Included in the Prior Art Database: 2005-Jan-28
Document File: 2 page(s) / 38K

Publishing Venue

IBM

Related People

Haug, W: AUTHOR [+2]

Abstract

Control storage applications permit part of the stored microcode to be fixed and thus read-only storage (ROS) cells to be used in conjunction with normal random-access memory (RAM) cells in one memory design.

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 100% of the total text.

Page 1 of 2

Static Memory Composed of Compatible RAM/ROS Cells

Control storage applications permit part of the stored microcode to be fixed and thus read-only storage (ROS) cells to be used in conjunction with normal random-access memory (RAM) cells in one memory design.

A standard 6-device cell T1 to T6 and its connection to the true and complement bit lines BLT, BLC is shown in the figure.

In addition, a ROS cell T7 is attached to the same bit lines by programmable vias. Depending upon the logical information, either the true or complement bit line is connected to the drain of T7. The layout of this ROS cell, optimized for the same bit pitch, is determined by the 6-device RAM cell. This approach affords a very dense RAM/ROS memory with flexible partitions.

The advantages of such a memory composed of RAM and ROS cells are:

The size of the entire array macro is drastically

reduced.

The lower bit line capacitance leads to

performance gains.

Minimum changes are required to implement ROS

cells in a RAM design.

1

Page 2 of 2

2

[This page contains 3 pictures or other non-text objects]