Method and apparatus for providing ROM in an integrated circuit having update through single substance layer modification capability
US5590069A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 17, 1994 |
| Grant date | Dec 31, 1996 |
| Priority date | — |
| Expiry date | Oct 17, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C17/12
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A ROM circuit that can be modified via the alteration of any one of a set of substance layers is described. The ROM circuit includes a set of ROM cells each of which provide one bit of data used to construct the fixed binary number. Each ROM cell includes a set of circuits that can be placed in either a first or second state via modification of a single substance layer that is different for each circuit, and generates a signal in a logic state that depends on whether the number of circuits in the first state is odd or even. When a design revision occurs the state of one of the circuits from the set of circuits is modified to update the fixed binary number using one of the substance layer already being modified during the course of the design revision.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.