Programmable logic device having configurable logic blocks with user-accessible input multiplexers

A configurable logic block on an integrated circuit, wherein the integrated circuit includes a signal source external to the configurable logic block, the configurable logic block comprising:

• a function generator having first and second input terminals;
• a first multiplexer having a plurality of input terminals, a select terminal, and a first multiplexer output terminal, wherein the first multiplexer output terminal is connected to the first input terminal of the function generator;
• a second multiplexer having a plurality of input terminals, a select terminal, and a second multiplexer output terminal, wherein the second multiplexer output terminal is connected to the second input terminal of the function generator;
• a first control terminal connected to the select terminal of the first multiplexer;
• a second control terminal connected to the select terminal of the second multiplexer;
• and
• a third multiplexer having an input terminal connected to the first control terminal and an output terminal connected to the select terminal of the first-mentioned multiplexer,
• wherein the first and second control terminals are adapted to receive input signals from the signal source external to the configurable logic block.

A configurable logic block on an integrated circuit, wherein the integrated circuit includes a signal source external to the configurable logic block, the configurable logic block comprising:

• a. a function generator having first and second input terminals;
• b. a first multiplexer having a plurality of input terminals, a select terminal, and a first multiplexer output terminal, wherein the first multiplexer output terminal is connected to the first input terminal of the function generator;
• c. a second multiplexer having a plurality of input terminals, a select terminal, and a second multiplexer output terminal, wherein the second multiplexer output terminal is connected to the second input terminal of the function generator;
• d. a first control terminal connected to the select terminal of the first multiplexer;
• and
• e. a second control terminal connected to the select terminal of the second multiplexer;
• f. wherein the first and second control terminals are adapted to receive input signals from the signal source external to the configurable logic block.

A programmable logic device comprising:

• a. a plurality of configurable logic blocks, each logic block including:
• i. a function generator having first and second input terminals;
• ii. a multiplexer having a plurality of input terminals, a select terminal, and a multiplexer output terminal, wherein the multiplexer output terminal is connected to the first input terminal of the function generator;
• and
• iii. a look-up table having:
• (1) an output terminal connected to the select terminal of the multiplexer;
• and
• (2) an input terminal adapted to receive a first input signal from a first signal source external to the configurable logic block;
• and
• b. a matrix of programmable interconnect lines separating ones of the configurable logic blocks, wherein the interconnect lines are configured to selectively interconnect ones of the configurable logic blocks via the plurality of input terminals of the multiplexer.

A programmable logic device comprising:

• a plurality of configurable logic blocks, each logic block including a function generator having a function-generator input terminal;
• a matrix of programmable interconnect lines separating ones of the configurable logic blocks, wherein the interconnect lines are configured to selectively interconnect ones of the configurable logic blocks;
• and
• means for dynamically connecting selected ones of the interconnect lines to the function-generator input terminal,
• wherein the means for dynamically connecting selected ones of the interconnect lines to the function-generator input terminal comprises a look-up table.

A configurable logic block on an integrated circuit, the configurable logic block comprising:

• a function generator having first and second input terminals;
• a multiplexer having a plurality of input terminals, a select terminal, and a multiplexer output terminal, wherein the multiplexer output terminal is connected to the first input terminal of the function generator;
• a control terminal connected to the select terminal, the control terminal adapted to receive an input signal from a signal source external to the CLB;
• and
• a look-up table having:
• a. an input terminal connected to the control terminal;
• and
• b. an output terminal connected to the select terminal of the multiplexer.

A configurable logic block on an integrated circuit, the configurable logic block comprising:

• a function generator having first and second input terminals;
• a multiplexer having a plurality of input terminals, a select terminal, and a multiplexer output terminal, wherein the multiplexer output terminal is connected to the first input terminal of the function generator;
• a control terminal connected to the select terminal, the control terminal adapted to receive an input signal from a signal source external to the CLB;
• and
• a second multiplexer having an input terminal connected to the control terminal and an output terminal connected to the select terminal of the first-mentioned multiplexer.

A programmable logic device comprising:

• a. a plurality of configurable logic blocks, each logic block including a function generator having a function-generator input terminal;
• b. a matrix of programmable interconnect lines separating ones of the configurable logic blocks, wherein the interconnect lines are configured to selectively interconnect ones of the configurable logic blocks;
• and
• c. means for dynamically connecting selected ones of the interconnect lines to the function-generator input terminal.