Semiconductor cell for neural network employing a four-quadrant multiplier

[54] SEMICONDUCTOR CELL FOR NEURAL NETWORK EMPLOYING A FOUR-QUADRANT MULTIPLIER

[75] Inventors: Mark A. Holler, Palo Alto; Simon M.

Tam, Redwood City; Ronald G.
Benson, Pasadena; Hernan A. Castro,
Shingle Springs, all of Calif.

[73] Assignee: Intel Corporation, Santa Clara, Calif.

[21] Appl. No.: 283,553

[22] Filed: Dec. 9, 1988

Related U.S. Application Data

[63] Continuation-in-part of Ser. No. 225,035, Jul. 27, 1988.

[51] Int. CI.5 G06G 7/12

[52] U.S. CI 307/201; 307/464;

307/498; 307/529; 364/513

[58] Field of Search 307/201, 464, 465, 478,

307/498, 501, 529; 364/513, 807; 365/184-185

[56] References Cited

U.S. PATENT DOCUMENTS

3,906,296 8/1971 Maserjian et al 357/24 X

4,660,166 4/1987 Hopfield 364/807

4,695,979 9/1987 Tuvell et al 365/185

4,742,492 5/1988 Smayling et al 365/185 X

4,760,437 7/1988 Denker et al 357/30

4,773,024 9/1988 Faggin et al 364/513

4,782,460 11/1988 Spencer 307/201 X

4,873,661 10/1989 Tsividis 364/807

4,874,963 10/1989 Alspecfor 307/201

4,875,183 10/1989 Grafetal 307/201 X

FOREIGN PATENT DOCUMENTS

0040251 11/1980 European Pat. Off. .

0121464 3/1984 European Pat. Off. .

0138439 9/1984 European Pat. Off. .

2049278 4/1980 United Kingdom .

OTHER PUBLICATIONS

"Programmable Analog Synapses for Microelectronic Neural Networks Using a Hybrid Digital-Analog Approach", by F. J. Mack, K. K. Moon, C. T. Yao and J. A. Modolo.

"Artificial Neurons Using Analog Multipliers", by Paul W. Hollis and John J. Paulos.

"Analysis and Design of Analog Integrated Circuits", by Paul R. Grey and Robert G. Meyer.

Primary Examiner—David Hudspeth

Attorney, Agent, or Firm—Blakely, Sokoloff, Taylor &

Zafman

[57] ABSTRACT

A synapse cell for use in providing a weighted connection strength is disclosed. The cell employs a four-quadrant multiplier and a pair of floating gate devices. Various charge levels are programmed onto the floating gate devices, establishing weight and reference levels. These levels affect the current flowing through the multiplier. The output of the cell thus becomes a multiple of the input and the programmed charge difference.

19 Claims, 6 Drawing Sheets