Gregory L Davis

US Patent:

54716683, Nov 28, 1995

Filed:

Jun 15, 1994

Appl. No.:

8/259819

Inventors:

Eric G. Soenen - Plano TX
Gregory B. Davis - Allen TX
Thomas Adkins - Coppell TX
Russell K. MacDonald - Plano TX

Assignee:

Texas Instruments Incorporated - Dallas TX

International Classification:

H04B 900
H04Q 100
H04M 1100

US Classification:

455352

Abstract:

An integrated circuit configurable as a transmitter/receiver includes learn capabilities that allows a receiver IC to memorize the identification pattern of a specific transmitter.

US Patent:

55984754, Jan 28, 1997

Filed:

Mar 23, 1995

Appl. No.:

8/408874

Inventors:

Eric G. Soenen - Plano TX
Gregory B. Davis - Allen TX
Angie Dycus - Plano TX

Assignee:

Texas Instruments Incorporated - Dallas TX

International Classification:

H04L 932
H04L 900

US Classification:

380 23

Abstract:

A remote control access system uses a transmitter and a receiver. The transmitter generates an encrypted identification code which the receiver decrypts and grants access to the system if the decrypted code matches an identification code stored in the receiver. The encryption occurs by taking a 40 bit identification code and forming 5 bytes (8 bytes each). The 5 bytes are logic exclusive OR'd to form a 5 byte wide encrypted code. Decryption occurs by performing the opposite exclusive OR operation on the 5 byte wide encrypted code to convert it back to the 5 byte identification code. The 4 most significant bytes of the decrypted code are compared against the 4 most significant bytes of the previous stored decrypted code in the receiver. If the comparison yields a zero, this means the least significant byte will be within 2. sup. 8 or 256 of each other and access will be granted.

US Patent:

60466804, Apr 4, 2000

Filed:

Jun 15, 1994

Appl. No.:

8/260148

Inventors:

Eric G. Soenen - Plano TX
Gregory B. Davis - Allen TX

Assignee:

Texas Instruments Incorporated - Dallas TX

International Classification:

H04Q 100

US Classification:

34082531

Abstract:

An integrated circuit (IC) configurable as transmitter/receiver includes a method of preventing unauthorized learning and reproduction of an access code as a security measure. When the IC is configured as a receiver and placed in the learn mode, a flag is set in a memory of a microcontroller. If later configured as a transmitter, the microcontroller checks the flag upon power up and if the flag is set, the stored code is randomized so transmission of it is impossible.

US Patent:

58323775, Nov 3, 1998

Filed:

Oct 26, 1995

Appl. No.:

8/503965

Inventors:

Eric G. Soenen - Plano TX
Gregory B. Davis - Allen TX
Thomas Adkins - Coppell TX
Russell K. MacDonald - Plano TX

Assignee:

Texas Instruments, Incorporated - Dallas TX

International Classification:

H04B 900

US Classification:

455352

Abstract:

An integrated circuit configurable as a transmitter/receiver includes learn capabilities that allows a receiver IC to memorize the identification pattern of a specific transmitter.

US Patent:

55725554, Nov 5, 1996

Filed:

Jun 15, 1994

Appl. No.:

8/259820

Inventors:

Eric G. Soenen - Plano TX
Gregory B. Davis - Allen TX

Assignee:

Texas Instruments Incorporated - Dallas TX

International Classification:

H04L 700
H04L 2706
H04L 2700

US Classification:

375364

Abstract:

A transmitted data stream in a remote control system is a serial data stream having a synchronization sequence and a data sequence. The data sequence is encoded into a symbol comprised of a series of data bits wherein a 110 may represent a logic 1 and a 011 may represent a logic 0. A self adaptive filter adjusts its gain and offset to determine the duration of one bit. Providing a serial code format wherein the synchronization sequence has a smiller duty cycle as the duty cycle of a symbol aids the self adaptive filter to set its threshold switching level accurately and quickly, thus aiding the receiver to decode the transmitted data stream.