Cswitch Corporation

Agate Logic, Inc.

Velogix, Inc.

Chandra Mulpuri

Ravi S Sunkavalli

Hare Krishna Verma

Manoj Gunwani

Sudip K Nag

Bo Hu

Ashok Vittal

Conrad Kong

Elliott Delaye

A programmable logic structure is disclosed employing input logic routing cell (ILRC) multiplexers and output logic routing cell (OLRC) multiplexers for making local connections between dedicated logic cells. In a simple programmable logic structure, a dedicated logic cell (DLC) is implemented in a programmable logic structure comprising multiple ILRC multiplexers for port A and multiple OLRC multiplexers for port B. In a multi-level programmable logic structure, multiple columns of dedicated logic cells is designed with columns of dedicated local cells adjacent to each other where each DLC column is used to implement a particular logic function. In a first embodiment, local connections can be made between dedicated logic cells, e.g. an OLRC in a first DLC at level L making local point-to-point connections to an ILRC in a second DLC at level L+1. In a second embodiment, local connections can be made from any other dedicated logic cells, whether positioned horizontally or vertically relative to a relative point or multiplexer, and from any offset from a current logic and routing cell (LRC). In a third embodiment, local connections can be made by stitching a first OLRC to a second OLRC (for connecting to an ILRC), which allows lines from other columns or levels of DLC to reach an ILRC for a fast local interconnect.

Programmable logic cells with local connections

A dedicated logic cell in a programmable logic structure is described that comprises the following primary components: a configurable logic function or look-up table (LL), a dedicated logic function (DL), a sequential logic function (LS), and a control logic function (LC). In this illustration, the dedicated logic cell comprises two configurable logic functions, two sequential logic functions, a dedicate logic function, and a control logic function. In a first embodiment, the dedicated logic cell is constructed with a combination of configurable logic functions that are coupled to a dedicated logic function in order to perform a four 2-input function, an AND function, an OR function, or an XOR function. In a second embodiment, the dedicated logic cell is constructed with a combination of configurable logic functions that are coupled to a dedicated logic function in order to perform a four 2-to-1 multiplexer function. In a third embodiment, the dedicated logic cell is constructed with a plurality of configurable logic functions that operate as a two 6-input function with separate inputs. In a fourth embodiment, the dedicated logic cell is constructed with a combination of a configurable logic function with sequential logic functions that operate as a loadable, resettable, clearable shift register. In a fifth embodiment, the dedicated logic cell is constructed with a combination of configurable logic functions, a dedicated logic function, and sequential logic functions that operate as an accumulator.

Dedicated logic cells employing sequential logic and control logic functions

A dedicated logic cell in a programmable logic structure is described that comprises the following primary components: a configurable logic function or look-up table (LL), a dedicated logic function (DL), a sequential logic function (LS), and a control logic function (LC). In this illustration, the dedicated logic cell comprises two configurable logic function, two sequential logic functions, a dedicate logic function, and a control logic function. In a first embodiment, the dedicated logic cell is constructed with a combination of configurable logic functions that are coupled to a dedicated logic function in order to perform a four 2-input function, an AND function, an OR function, or an XOR function. In a second embodiment, the dedicated logic cell is constructed with a combination of configurable logic functions that are coupled to a dedicated logic function in order to perform a four 2-to-1 multiplexer function. In a third embodiment, the dedicated logic cell is constructed with a plurality of configurable logic functions that operate as a two 6-input function with separate inputs. In a fourth embodiment, the dedicated logic cell is constructed with a combination of a configurable logic function with sequential logic functions that operate as a loadable, resettable, clearable shift register. In a fifth embodiment, the dedicated logic cell is constructed with a combination of configurable logic functions, a dedicated logic function, and a sequential logic functions that operate as an accumulator.

A programmable logic structure is disclosed that has a set of dedicated lines which extend internally throughout different dedicated logic cells within a logic and routing block (LRB), extend from a previous logic routing block to the present logic and routing block, or extend from the present logic and routing block to the next logic and routing block. One set of dedicated lines from a first logic and routing block can be stitched to another set of dedicated lines of a second logic and routing block for extending the reach as well as bypassing a logic and routing block, or bypassing a dedicated logic cell in the same logic and routing block. The dedicated lines between logic and routing blocks allow a logic and routing block to receive more inputs from its own switch box or to drive more outputs than provided by the logic and routing block as specified by a given function.

Growing community of inventors

San Jose, CA, United States of America

Chandra Mulpuri