Christopher J Carroll

Address:

12715 Connell Dr, Overland Park, KS 66213

VIN:

JTHBJ46G972002327

Make:

LEXUS

Model:

ES 350

Year:

2007

US Patent:

48602280, Aug 22, 1989

Filed:

Feb 24, 1987

Appl. No.:

7/018148

Inventors:

Christopher J. Carroll - Streamwood IL

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

G01B 700
G06F 700

US Classification:

364561

Abstract:

Disclosed is a technique for storing a count of incrementally increasing data exclusively in EEPROM using semaphores to avoid significant losses, as a result of power downs, greater than a single least significant bit in accuracy. The disclosed embodiment includes a first EEPROM register, comprised of 256 bits, for storing 256 incremental count increases, each bit is used to record an incremental count increase. A pair of 16 bit EEPROM registers is provided for incrementally storing updated count information in response to the first EEPROM register overflowing. Semaphores are provided for indicating whether or not the incrementally increasing count information has been at least partially stored in the pair of registers. Once an overflow from the first register is detected, the semaphores are checked to determine in what stage the update to the pair of registers was left (in case of power down). In response to the semaphore information, the overflow is stored in the pair of registers for a complete update of the count, and the semaphores are appropriately updated to so indicate.