Method and apparatus for firmware upgrades in embedded systems
US5566335A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 16, 1993 |
| Grant date | Oct 15, 1996 |
| Priority date | — |
| Expiry date | Mar 16, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F8/66
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Firmware updates for embedded systems are accomplished by using PROM in favor of conventional ROM, dividing the PROM into pages zero, one, two, etc., that can each contain an entire version of the embedded system. Pages of PROM are addressable by MSB address bits that originate from a circuit that selects page zero upon power-up, and that is responsive to a command in the firmware of the embedded system to increment the value of the MSB address bits. Upon initial fabrication, a product containing the embedded system has entirely unprogrammed PROM. An initial embedded system is zapped into page zero when the product is tested after being turned on for the first time. Replacement versions can be zapped into successive pages as the need arises. Each version includes an initialization routine and its own Get Next Page (GNP) bit. If a version is superseded by another, the old version indicates this by a GNP bit that gets programmed on the old page at the same time the replacement version is zapped into the new page. When that GNP bit is checked by its initialization routine the page selecting MSB address bits are incremented and the micro-processor executing the embedded system is reset…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.