US 5,491,431 AGranted

Logic module core cell for gate arrays

AssigneeTexas Instruments Incorporated

InventorMitra Nasserbakht

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Abstract

A logic module for use in gate arrays and the like includes five two input multiplexers 50, 52, 54, 56, 58. The module includes 10 data input terminals I1, I2, I3, I4, I5, I6, I7, I8, I9, I10. The first input terminals I1, I2 are connected to the data input terminals of multiplexer 50. Inputs I3, I4 and I5 are connected respectively to the select, the first data and second data inputs to multiplexer 52. Inputs I6, I7 are connected to the data inputs of multiplexer 54. Inputs I8, I9, I10 are connected to the first data, second data and select inputs to multiplexer 56. The output of multiplexer 52 is connected to the select input to multiplexers 50 and 54. The output of multiplexer 56 is connected to the select input to multiplexer 58 while the outputs of multiplexers 50 and 54 are respectively connected to the first and second data input to multiplexer 58. The output of multiplexer 58 comprises the logic circuit output O.

Claims6

Dependent claims

A logic module core cell for performing a plurality of logic functions comprising, in combination:

a first, second, third, fourth and fifth multiplexer circuit, each multiplexer circuit with a first and a second data input and a selector input for selecting which said data input is gated to the multiplexer output;
said first multiplexer circuit having its first and second data input comprise a first and second logic module input;
said second multiplexer circuit having its first and second data input and its selector input comprise a third, fourth and fifth logic module input
said third multiplexer circuit having its first and second data input comprise a sixth and seventh logic module input;
said fourth multiplexer circuit having its first and second data input and its selector input comprise a eighth, ninth and tenth logic module input;
the output of said second multiplexer circuit being connected to the selector input to said first and third multiplexer;
and
the output of said first and third multiplexer circuit being connected respectively to said first and second data input to said fifth multiplexer circuit, the output of said fourth multiplexer being connected to the selector input to said fifth multiplexer circuit the output of said fifth multiplexer circuit comprising the output of said logic module.

5 more elements

A logic configuration for performing a plurality of logic functions comprising, in combination:

a first two input multiplexer with a select input, a first and second data input and an output;
a second two input multiplexer with a select input, a first and second data input and an output;
a third two input multiplexer with a select input, a first and second data input and an output;
interconnection means for connecting the output of said second two input multiplexer to said select input to said first two input multiplexer and to said select input to said third two input multiplexer;
the inputs to said logic configuration comprising said first and second data input to said first multiplexer, said first and second data input to said third multiplexer, said first and second data input to said second multiplexer and said select input to said second multiplexer, the output of said logic configuration comprising said output of said first multiplexer;
and
circuit means connected to the output of said first and said third multiplexer for selecting either said first or said third multiplexer output as the output of the logic configuration.

4 more elements

Dependencies are inferred from the claim text.