Integrated circuit with identification signal writing circuitry distributed on multiple metal layers
US5787012A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 17, 1995 |
| Grant date | Jul 28, 1998 |
| Priority date | — |
| Expiry date | Nov 17, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/0002
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An integrated circuit includes a first metal layer with first layer identification signal writing circuitry connections to produce first metal layer circuit identification signals. The integrated circuit also has a second metal layer with second layer identification signal writing circuitry connections to produce second metal layer circuit identification signals. Logic circuitry in the first metal layer has input connections to the first layer identification signal writing circuitry connections and the second layer identification signal writing circuitry connections. The logic circuitry combines the first metal layer circuit identification signals and the second metal layer circuit identification signals to produce a circuit identification number. The value of the circuit identification number can be changed by altering the first layer identification signal writing circuitry connectors or the second layer identification signal writing circuitry connections. Thus, the value of the circuit identification number can be easily changed at the metal layer at which revisions are made.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.