Apple Inc.

Oracle America, Inc.

Sun Microsystems, Inc.

Shyam Sundar Balasubramanian

Dennis L Wendell

Jun Liu

Yolin Lih

Ajay Bhatia

Daniel Fung

Gerard Richard Williams

John H Mylius

Mridul Agarwal

Rohit Kumar

Conrado Blasco-Allue

Rajat Goel

Harsha Krishnamurthy

Muthukumaravelu Velayoudame

Christopher S Thomas

In some embodiments, a register file circuit design process includes instructing an automated integrated circuit design program to generate a register file circuit design, including providing a cell circuit design and instructing the automated integrated circuit design program to generate a selection design, a pre-decode design, and a data gating design. The cell circuit design describes a plurality of selection circuits that have a particular arrangement. The selection design describes a plurality of replica circuits that include respective pluralities of selection circuits having the particular arrangement. The pre-decode design describes a pre-decode circuit configured to identify a plurality of entries identified by a portion of a write instruction. The data gating design describes data gating circuits configured, in response to the pre-decode circuit not identifying respective entries, to disable data inputs to respective write selection circuits connected to the respective entries.

Register file circuit design process

In an embodiment, a processor includes a multi-level dispatch circuit configured to supply operations for execution by multiple parallel execution pipelines. The multi-level dispatch circuit may include multiple dispatch buffers, each of which is coupled to multiple reservation stations. Each reservation station may be coupled to a respective execution pipeline and may be configured to schedule instruction operations (ops) for execution in the respective execution pipeline. The sets of reservation stations coupled to each dispatch buffer may be non-overlapping. Thus, if a given op is to be executed in a given execution pipeline, the op may be sent to the dispatch buffer which is coupled to the reservation station that provides ops to the given execution pipeline.

Multi-level dispatch for a superscalar processor

A memory device having a split power switch is provided to improve the writeability of static random access memory (SRAM) cells without adversely compromising their stability. For example, various split power switch circuits are used to permit the voltage or current of a power supply line connected with one side of an SRAM cell to drop during write operations. This drop weakens one side of the SRAM cell and reduces the drive-fight between transistors of the SRAM cell and external write circuitry. As a result, the minimum voltage for writing new logic states into the SRAM cell is reduced to permit overall lower operating voltages for the SRAM cell and related circuitry. By continuing to maintain a second side of the SRAM cell at the reference voltage or current, the SRAM cell can successfully switch to a newly written logic state.

Memory device with split power switch

An elastic power header device and methods of operation are provided to improve the read margin of static random access memory (SRAM) cells by increasing read stability, reducing read disturbance and improving the Signal to Noise Margin (SNM) figure of merit. For example, various implementations of an elastic power header device are utilized as programmable resistances to permit the power supply lines to reach a maximum voltage. Allowing the power supply lines to reach the reference voltage allows more flexibility in read margin and read stability. Furthermore, this additional flexibility can be controlled by means for adjusting a voltage. This adjustment voltage can fine-tune the programmable resistances so that the read margin can be more conveniently controlled.

Elastic power for read margin

An elastic power header device and methods of operation are provided to improve both the read and the write margin of static random access memory (SRAM) cells by increasing read stability, reducing read disturbance and improving the Signal to Noise Margin (SNM) figure of merit. For example, various implementations of an elastic power header device are utilized as programmable resistances to permit the power supply lines to reach a maximum voltage. Allowing the power supply lines to reach the reference voltage allows more flexibility in read margin, write margin and read stability. Furthermore, this additional flexibility can be controlled by means for adjusting a voltage. This adjustment voltage can fine-tune the programmable resistances so that the read margin and the write margin can be more conveniently controlled.

Elastic power for read and write margins

Growing community of inventors

Santa Clara, CA, United States of America

Shyam Sundar Balasubramanian