Flash EPROM control with embedded pulse timer and with built-in signature analysis
US5872794A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 29, 1997 |
| Grant date | Feb 16, 1999 |
| Priority date | — |
| Expiry date | Oct 29, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C29/20
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Built-In-Logic-Block-Observation registers BILBO are coupled to the output of a Control-Read-Only-Memory CROM in the write-state-machine of a flash EPROM. The Built-In-Logic-Block-Observation registers BILBO include master/slave latches M/SL, shadow latches SHL, and other logic circuitry that enable the various modes of operation required for pulse timing and for signature analysis. During operation a pre-defined FLASH command sequence requests a Control-Read-Only-Memory CROM signature analysis that executes a set of instructions causing the Built-In-Logic-Block-Observation registers BILBO to be placed in the Multiple-Input-Signature-Register Mode and that steps through the Control-Read-Only-Memory CROM until all valid addresses have been evaluated. The resultant Control-Read-Only-Memory CROM signature is then scanned out and verified. The invention eliminates the need for a separate stand-alone Linear-Feedback-Shift-Register LFSR used for pulse timing. The contents of the Control-Read-Only-Memory CROM are verified without the necessity for time-consuming scanning-out of each word.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.