Apple Inc.

Shahzad Nazar

Mohamed Hassan Abu-Rahma

Ajay Bhatia

Jaroslav Raszka

Amrinder S Barn

Victor Zyuban

Yildiz Sinangil

Jaemyung Lim

Aravind Kandala

Bharan Giridhar

Mayur V Joshi

Greg M Hess

Shingo Suzuki

Emre Alptekin

Xin Miao

Saurabh P Sinha

Jiangyi Li

A memory device layout that implements SRAM cells with stacked transistors is disclosed. The memory utilizes both topside metal routing and backside metal routing for routing of bitlines between bit cells with stacked transistors and logic cells coupled to the bit cells.

SRAM macro design architecture

A compute-memory circuit included in a computer system includes multiple data storage cells and multiplier circuits. The data storage cells store weight values associated with a first operand. The multiplier circuits are coupled to a global bit line and receive the weight values via local bit lines coupled to the data storage cells. Using the received weight values and activation signals indicative of a second operand, the multiplier circuits modify a voltage level of the global bit line. The resultant voltage level on the global bit line is indicative of a product of the first and second operands, and can be converted to a digital value using an analog-to-digital converter circuit.

Performing multiple bit computation and convolution in memory

An apparatus includes a memory circuit that includes a plurality of sub-arrays. The memory circuit is configured to implement a retention mode according to test information indicating voltage sensitivities for the plurality of sub-arrays. The apparatus also includes a voltage control circuit coupled to a power supply node. The voltage control circuit is configured, in response to activation of the retention mode for the plurality of sub-arrays, to generate, based on the test information, at least two different retention voltage levels for different ones of the plurality of sub-arrays. The at least two different retention voltage levels are lower than a power supply voltage level of the power supply node.

Retention voltage management for a volatile memory

A memory array that provides an internal retention voltage without a voltage regulator is disclosed. The memory array includes a first group of bit cells coupled between the power supply rail and a ground switch and a second group of bit cells coupled to a retention select circuit. The retention select circuit is coupled to the ground for the first group of bit cells and the power supply rail. The ground switch and the retention select circuit may be operated to switch the bit cells between a nominal operating voltage and a retention voltage. The retention voltage is provided during inactive periods of the memory array to maintain data in the bit cells during the inactive periods.

Sram bit cell retention

Memory circuits used in computer systems may have different operating modes. In a retention mode, a voltage level of an array power supply node coupled to memory cells included in the memory circuit is reduced to a level sufficient to retain data, but not to perform read and write operations to the memory cells. A power converter circuit may be configured to generate the retention voltage level, and adjust the retention voltage level using a leakage current of dummy memory cells included in the memory circuit.

Retention voltage generator circuit

A power switch control circuit is disclosed. A sensor circuit may determine a leakage current of a power switch coupled to a power supply signal and a power terminal of a circuit block. The power switch may be configured to selectively couple or decouple the circuit block from the power supply signal using a switch control signal. The switch control circuit may, in response to receiving a request to open the power switch, determine a target voltage level that is greater than a voltage level of the power supply signal for the switch control signal using the leakage current, and transition the switch control signal from an initial voltage to the target voltage level.

Low leakage power switch

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Fremont, CA, United States of America

Shahzad Nazar