Electrical circuit for setting internal chip functions without dedicated configuration pins
US5608341A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 9, 1995 |
| Grant date | Mar 4, 1997 |
| Priority date | — |
| Expiry date | May 9, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K19/1732
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A circuit for selecting different applications based upon the manner in which external elements are attached. The selection of the applications is controlled based on the potential detected at a pin immediately following reset. The voltage at a node of the application sense pin is compared with a reference voltage. The pin used to sense the application is used as a sense immediately after reset has occurred. After this it can function as either an output or an input. A flip-flop is connected such that the output of the application sense pin and the condition of reset is directed appropriately to the flip-flop. When the condition of not-in-reset is sensed, the flip-flop latches to a first condition or to a second condition based on the potential at the application sense pin. A binary select allows 2.sup.n different applications to be selected where n is the number of pins used to select the application. When a first binary code is sensed, a first application is implemented. When a second binary code is existent, a second application is implemented. The application sense may be used to select an LED display scheme or another application function.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.