The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 16, 2001
Filed:
Dec. 04, 1992
Frederick Johannes Bruwer, Pretoria, ZA;
Willem Smit, Pretoria, ZA;
Gideon Jacobus K{umlaut over (u)}hn, Pretoria, ZA;
Microchip Technology Incorporated, Chandler, AZ (US);
Abstract
Encoder and decoder microchips suitable for use in secure unidirectional remote control devices. The encoder microchip includes circuits for performing and encoding function on an identification number embedded in the microchip and a combination of a characterization number and a stepping counter value, so as to generate a transmission value which is only decidable by a related decoding function having access to the same identification number. The decoder microchip includes circuits for decoding the transmission value into a decoded characterization number and a decoded counter value and circuits for comparing the decoded counter value with a decoded counter value range. The encoder and decoder microchips are also provided with means for synchronizing the decoder microchip with a particular encoder microchip which has generated a synchronization command.