Apple Inc.

P.a. Semi, Inc.

Broadcom Corporation

Sribalan Santhanam

Vincent R Von Kaenel

Brian J Campbell

Daniel C Murray

Gregory Stuart Scott

Keith Alan Cox

Norman Jay Rohrer

John Gregory Dorsey

David A Kruckemyer

Antonietta Oliva

Honkai Tam

Ashish R Jain

Jung-Cheng Yeh

Sung Wook Kang

Sanjay P Zambare

Mohamed H Abu-Rama

In one embodiment, an integrated circuit includes at least one logic circuit supplied by a first supply voltage and at least one memory circuit coupled to the logic circuit and supplied by a second supply voltage. The memory circuit is configured to be read and written responsive to the logic circuit even if the first supply voltage is less than the second supply voltage during use. In another embodiment, a method includes a logic circuit reading a memory cell, the logic circuit supplied by a first supply voltage; and the memory cell responding to the read using signals that are referenced to the first supply voltage, wherein the memory cell is supplied with a second supply voltage that is greater than the first supply voltage during use.

Integrated circuit with separate supply voltage for memory that is different from logic circuit supply voltage

In an embodiment, the amount of supply voltage guardband to prevent incorrect operation due to aging effects may be modeled using an IC-specific age model generated early in the product life cycle of the IC. For example, high temperature operating life (HTOL) testing may be performed at multiple temperatures and/or voltages to develop the IC-specific age model. The IC-specific age model may be more accurate then the calculations used to develop guardband voltage as discussed previously, which rely on the aging of a single transistor. The IC-specific age model may be used along with monitoring of the aging effects during operation of the IC to predict an amount of increased guardband voltage that is currently desirable to apply to the IC. The predicted amount may vary from about zero when the IC is new to the full amount of guardband voltage when the IC is nearing end of life.

Reliability guardband compensation

A memory circuit may include a pair of cross-coupled inverters configured to store a bit of data and a first transistor coupled to a first node of the pair of cross-coupled inverters. A plurality of transistors that form the pair of inverters have a first nominal threshold voltage. The first transistor is coupled to a first bit line, and has a second nominal threshold voltage that is lower than the first nominal threshold voltage. The first transistor may be a write transistor and another write transistor having the second nominal threshold voltage is coupled to the other node of the pair of cross-coupled inverters. A register file may include a bit storage section that includes at least one pair of the cross-coupled inverters; a write transistor section and a read transistor section having the second nominal threshold voltage.

Multiple threshold voltage register file cell

In one embodiment, an integrated circuit comprises at least one logic circuit supplied by a first supply voltage and at least one memory circuit coupled to the logic circuit and supplied by a second supply voltage. The memory circuit is configured to be read and written responsive to the logic circuit even if the first supply voltage is less than the second supply voltage during use. In another embodiment, a method comprises a logic circuit reading a memory cell, the logic circuit supplied by a first supply voltage; and the memory cell responding to the read using signals that are referenced to the first supply voltage, wherein the memory cell is supplied with a second supply voltage that is greater than the first supply voltage during use.

Growing community of inventors

Palo Alto, CA, United States of America

Sribalan Santhanam