Enabling special modes within a digital device
US7603601B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 16, 2006 |
| Grant date | Oct 13, 2009 |
| Priority date | — |
| Expiry date | Jan 20, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C29/46
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A special mode key match comparison module has N-storage elements and a special mode key match comparator. The N-storage elements accumulate a serial data stream, and then determine whether a digital device should operate in a normal user mode, in a public programming mode, or in a particular private test mode. To reduce the possibility of accidentally decoding a false test or programming mode, the data stream has a sufficiently large number of N-bits to substantially reduce the probability of a false decode. To further reduce the possibility of accidentally decoding a programming or test mode, the special mode key match comparison module may be reset if less or more than N-clocks are detected during the accumulation of the N-bit serial data stream. The special mode key match data patterns may represent a normal user mode, a public programming mode, and particular private manufacturer test modes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.