Programmable logic device including bi-directional shift register
AssigneeSTMicroelectronics S.r.l.
InventorAnkur Bal
Life of this patent
Estimating the term…
Abstract
A programmable logic device may include a programmable interconnect structure and a plurality of configurable logic elements including data latches interconnected by the interconnect structure. At least one of the configurable logic elements may be configurable as both a shift register and a lookup table. Also, the shift register may be enabled to operate as a bi-directional shift register by the inclusion of a first circuit for configuring the data latches either as series-connected inverters during a shift operation or as data latches after each shift operation. A second circuit for selecting a direction of shifting may also be included, as well as a third circuit for supplying data to the input of the shift register as determined by the direction of shifting.
Claims31
A programmable logic device comprising:
- a plurality of configurable logic elements each comprising a data latch, and each data latch comprising a plurality of inverters, at least one of said configurable logic elements being configurable as both a bi-directional shift register and a lookup table;
- a programmable interconnect structure connecting said plurality of configurable logic elements together;
- first means for configuring said configurable logic elements as series connected inverters during a shift operation and as data latches thereafter;
- second means for selecting a direction of shifting;
- and
- third means for supplying data to an input of said bi-directional shift register based upon the direction of shifting.
A programmable logic device comprising:
- a plurality of configurable logic elements each comprising a data latch, and each data latch comprising a plurality of inverters, at least one of said configurable logic elements being configurable as both a bi-directional shift register and a lookup table;
- first circuitry for configuring said configurable logic elements as series connected inverters during a shift operation and as data latches thereafter;
- second circuitry for selecting a direction of shifting;
- and
- third circuitry for supplying data to an input of said bi-directional shift register based upon the direction of shifting.
An electronic device comprising:
- a plurality of programmable logic devices connected together to form a bi-directional shift register having a length greater than a length of an individual programmable logic device, each programmable logic device comprising
- a plurality of configurable logic elements each comprising a data latch, and each data latch comprising a plurality of inverters, at least one of said configurable logic elements being configurable as both a bi-directional shift register and a lookup table,
- first circuitry for configuring said configurable logic elements as series connected inverters during a shift operation and as data latches thereafter,
- second circuitry for selecting a direction of shifting, and
- third circuitry for supplying data to an input of said bi-directional shift register based upon the direction of shifting.
A method for using a programmable logic device comprising a plurality of configurable logic elements each comprising a data latch, each data latch comprising a plurality of inverters, and at least one of the configurable logic elements being configurable as both a bi-directional shift register and a lookup table, the method comprising:
- selecting a direction of shifting;
- supplying data to an input of the bi-directional shift register based upon the direction of shifting;
- and
- configuring the configurable logic elements as series connected inverters during a shift operation and as data latches thereafter.
Dependencies are inferred from the claim text.