High speed CMOS latch with alternate data storage and test functions
US4768167A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 30, 1986 |
| Grant date | Aug 30, 1988 |
| Priority date | — |
| Expiry date | Sep 30, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K3/356113
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A CMOS flip-flop circuit is disclosed which enables a single side pull-down operation for inputting test signals during a test mode and alternately a dual side push-pull operation for inputting data signals during the normal use of the circuit. A pair of inverter circuits selectively feed complementary data signals to opposite sides of a bistable circuit so that the circuit operates in the push-pull manner thereby decreasing the switching time of the flip-flop. A pair of transmission gates, which are coupled to outputs of the inverter circuits, electrically isolate any noise appearing at a data input from the bistable circuit. During a test mode of the flip-flop, a test signal is fed into one side of the bistable circuit and facilitates a single side pull-down operation of the flip-flop. Two such flip-flop circuits are concatenated in a push-pull cascaded connection to provide a shift register latch.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.