Cryptography – Key management – Having particular key generator
Patent
1994-03-07
1995-08-29
Lall, Parshotam S.
Cryptography
Key management
Having particular key generator
395728, 380 3, 364DIG2, 3649694, G06F 1214
Patent
active
054468647
ABSTRACT:
A microcontroller fabricated on a semiconductor chip has an on-chip EPROM program memory. The microcontroller is selectively configurable to operate in any one of a plurality of predetermined operating modes, including at least one secure microcontroller mode. A plurality of EPROM configuration fuses used for configuring the microcontroller and protecting its program memory from read, verify or write through any instruction initiated from other than a predetermined secure area of the chip, are mapped into the on-chip EPROM program memory as bits in respective address locations thereof. The value of a bit representing any one of said fuses is effective to determine the condition of the respective fuse. That condition is observed by reading the value of the respective bit for that fuse stored in the EPROM program memory. The chip security is enabled by configuring the microcontroller in a code protected mode by programming the bits representing the desired fuses in the EPROM program memory to effectively blow or erase each fuse according to the desired configuration.
REFERENCES:
patent: 4523271 (1985-06-01), Levien
patent: 4590552 (1986-05-01), Guttag
patent: 4648076 (1987-03-01), Schrenk
patent: 4698750 (1987-10-01), Wilkie et al.
patent: 4796235 (1989-01-01), Sparks et al.
patent: 4821240 (1989-04-01), Nakamura et al.
patent: 4843026 (1989-06-01), Ong et al.
patent: 4851894 (1989-07-01), de Ferron et al.
patent: 4864542 (1989-09-01), Oshima et al.
patent: 4890263 (1989-12-01), Little
patent: 4931993 (1990-06-01), Urushima
patent: 4975878 (1990-12-01), Boddu
patent: 5084843 (1992-01-01), Mitsuishi
patent: 5097445 (1992-03-01), Yamauchi
patent: 5175840 (1992-12-01), Sawase et al.
patent: 5206938 (1993-04-01), Fujioka
patent: 5251304 (1993-10-01), Sibigtroth et al.
Allen Ray
Berman Eric
Burghardt Martin
Padgaonkar Ajay
Ellis Richard L.
Lall Parshotam S.
Microchip Technology Inc.
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