Register access decade counting technique
US4839909A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 13, 1987 |
| Grant date | Jun 13, 1989 |
| Priority date | — |
| Expiry date | Nov 13, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K23/542
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An electronic counter such as for use in the odometer of a motor vehicle is provided comprising an array (10) of m rows and n columns of single flip-flop data latches and a central shifting unit (14). The central shifting unit (14) comprises a row of n data latches arranged to read data from and write data to each of the m rows of data latches of the array (10). In operation, the central shifting unit (14) reads data from a row of data latches of the array, performs a shift operation on the data and an invert operation on one of n data latches of the central shifting unit (14) and returns the data so operated on to the row of data latches in the array (10). By these steps, a counting operation in Johnson code is performed on the data. This invention uses less chip area than known counters.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.