Programmable logic device macrocell having exclusive lines for feedback and external input, and a node which is selectively shared for registered output and external input
US5414376A · kind A · utility
9Cited by
11References
9Claims
0Family size
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Inventor
Key dates
| Filing date | Aug 12, 1994 |
| Grant date | May 9, 1995 |
| Priority date | — |
| Expiry date | Aug 12, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K19/17716
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An improved programmable logic device (PLD) having a macrocell operable in a registered mode is disclosed. The improved PLD has exclusive lines for both registered feedback and for external input, both of which are fed into a single multiplexer. The output of the multiplexer is fed into the PLD's AND array. The external input line is coupled to the I/O terminal of the macrocell. A tri-state output buffer selectively decouples the I/O terminal from the macrocell output so that the I/O terminal may be employed to alternately receive a registered output signal from the macrocell or to send an external control signal to the AND array.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.