US 7,605,605 B2 · Programmable logic cells with local connections

Abstract

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.

Claims12

Dependent claims

A programmable logic structure for point-to-point local connections, comprising

an output logic and routing cell multiplexer in a first means at a first level;
and
a first input logic and routing cell multiplexer in a second dedicated logic at a second level, the output logic and routing cell multiplexer in the first dedicated logic cell at the first level making a direct point-to-point connection to the first input logic and routing multiplexer cell in the second dedicated logic cell at the second level without routing the connection through a switch circuit;
wherein the first dedicated logic cell comprises;
a first logic and routing cell;
and
a second logic and routing cell coupled to the first logic and routing cell, the first logic and routing cells including:
a first look-up table having a plurality of inputs for receiving a set of inputs and at least one output;
a second look-up table having a plurality of inputs for receiving the set of inputs and at least one output;
a third look-up table for receiving at least one input and generating at least one output;
and
a fourth-look-up table for receiving at least one input and generating at least one output;
a logic having inputs coupled to the first, second, third, fourth look-up tables and generating at least one output.

10 more elements

Dependencies are inferred from the claim text.

Programmable logic cells with local connections

Life of this patent

Programmable logic cells with local connections

Life of this patent

Abstract

Claims12