Apple Inc.

Per Hakan Hammarlund

Harshavardhan Kaushikkar

Gaurav Garg

James Vash

Lior Zimet

Steven R Hutsell

Lital Levy-Rubin

Eran Tamari

Sergio Kolor

Sagi Lahav

Gerard Richard Williams

Ramesh B Gunna

Brian P Lilly

Steven John Fishwick

Jonathan M Redshaw

Jeffry E Gonion

Srinivasa Rangan Sridharan

Shawn Munetoshi Fukami

Sergio V Tota

Liran Fishel

Jeff Gonion

Tzach Zemer

Samer Nassar

Roman Gindin

Manu Gulati

Wei Xu

Mohamed Hassan Abu-Rahma

Rohan U Mandrekar

Victor Zyuban

Tal Kuzi

Benjamin K Dodge

Jamie L Langlinais

Michael Bekerman

Charles E Tucker

Jaroslav Raszka

Alexander B Uan-Zo-li

Dany Davidov

Nir Leshem

Mark Pilip

Sambasivan Narayan

Opher D Kahn

Sung J Kim

Leonid Gitelman

Oren Betzalel

Dalia R Haim

Idan Nissel

Haim Hauzi

Robert O Bruckner

Hans L Yeager

Alfredo Kostianovsky

In an embodiment, a system includes a plurality of integrated circuits have subsets of a plurality of agents. The plurality of integrated circuits may have network segments implemented wholly (e.g., entirely) within the respective integrated circuits and may have segment to segment (S2S) network interface circuits to couple to other network segments of a plurality of network segment forming a network among the plurality of agents.

Segment to segment network interface

A system including a plurality of processor cores, a plurality of graphics processing units, a plurality of peripheral circuits, and a plurality of memory controllers is configured to support scaling of the system using a unified memory architecture.

Scalable system on a chip

A system may include multiple coherent agents, where a given coherent agent includes one or more caches configured to cache data. Memory controller circuitry may control one or more memory circuits from which the one or more caches are configured to cache data and maintain a directory that tracks which of the multiple coherent agent circuits is caching copies of a plurality of cache blocks and states of the cached copies in the multiple coherent agent circuits. A first agent may transmit a first request for a first cache block. The first agent may store, in request buffer circuitry, information corresponding to the first request then detect a second snoop from a second agent circuit to the first cache block. The first agent may absorb the second snoop, including to store information corresponding to the second snoop with the information corresponding to the first request in the request buffer circuitry.

Scalable cache coherency protocol

A chip design methodology and a set of integrated circuits that are taped out from a common design database are disclosed. The area of a full instance of the integrated circuit is defined, and one or more chop lines are defined to identify portions that will be removed for one or more partial instances. A variety of techniques and mechanisms are defined to permit the tape outs to occur from a common design database, so that the effort to tape out partial instances may be minimized beyond that to tape out the full instance.

Full die and partial die tape outs from common design

A power delivery sub-system included in a computer system employs a primary voltage regulator circuit that generates a primary supply voltage on a primary power supply node. The power delivery sub-system also includes multiple bypass voltage regulator circuits that source corresponding bypass currents to a local power supply nodes in an integrated circuit. The integrated circuit includes multiple circuit blocks coupled to corresponding ones of the local power supply nodes, and multiple local voltage regulator circuits coupled to the primary power supply node. When a voltage level of a given local power supply node drops below a threshold value, a corresponding local voltage regulator circuit sources a supply current to the given local power supply node.

Merged power delivery

In an embodiment, a system may support programmable hashing of address bits at a plurality of levels of granularity to map memory addresses to memory controllers and ultimately at least to memory devices. The hashing may be programmed to distribute pages of memory across the memory controllers, and consecutive blocks of the page may be mapped to physically distant memory controllers. In an embodiment, address bits may be dropped from each level of granularity, forming a compacted pipe address to save power within the memory controller. In an embodiment, a memory folding scheme may be employed to reduce the number of active memory devices and/or memory controllers in the system when the full complement of memory is not needed.

Hashing with soft memory folding

A scalable cache coherency protocol for system including a plurality of coherent agents coupled to one or more memory controllers is described. The memory controller may implement a precise directory for cache blocks from the memory to which the memory controller is coupled. Multiple requests to a cache block may be outstanding, and snoops and completions for requests may include an expected cache state at the receiving agent, as indicated by a directory in the memory controller when the request was processed, to allow the receiving agent to detect race conditions. In an embodiment, the cache states may include a primary shared and a secondary shared state. The primary shared state may apply to a coherent agent that bears responsibility for transmitting a copy of the cache block to a requesting agent. In an embodiment, at least two types of snoops may be supported: snoop forward and snoop back.

Techniques are disclosed relating to an I/O agent circuit. The I/O agent circuit may include one or more queues and a transaction pipeline. The I/O agent circuit may issue, to the transaction pipeline from a queue of the one or more queues, a transaction of a series of transactions enqueued in a particular order. The I/O agent circuit may generate, at the transaction pipeline, a determination to return the transaction to the queue based on a detection of one or more conditions being satisfied. Based on the determination, the I/O agent circuit may reject, at the transaction pipeline, up to a threshold number of transactions that issued from the queue after the transaction issued. The I/O agent circuit may insert the transaction at a head of the queue such that the transaction is enqueued at the queue sequentially first for the series of transactions according to the particular order.

Ensuring transactional ordering in I/O agent

An integrated circuit (IC) including a plurality of processor cores, a plurality of graphics processing units, a plurality of peripheral circuits, and a plurality of memory controllers is configured to support scaling of the system using a unified memory architecture. For example, the IC may include an interconnect fabric configured to provide communication between the one or more memory controller circuits and the processor cores, graphics processing units, and peripheral devices; and an off-chip interconnect coupled to the interconnect fabric and configured to couple the interconnect fabric to a corresponding interconnect fabric on another instance of the integrated circuit, wherein the interconnect fabric and the off-chip interconnect provide an interface that transparently connects the one or more memory controller circuits, the processor cores, graphics processing units, and peripheral devices in either a single instance of the integrated circuit or two or more instances of the integrated circuit.

In an embodiment, a system on a chip (SOC) comprises a semiconductor die on which circuitry is formed, wherein the circuitry comprises a plurality of agents and a plurality of network switches coupled to the plurality of agents. The plurality of network switches are interconnected to form a plurality of physical and logically independent networks. A first network of the plurality of physically and logically independent networks is constructed according to a first topology and a second network of the plurality of physically and logically independent networks is constructed according to a second topology that is different from the first topology. For example, the first topology may a ring topology and the second topology may be a mesh topology. In an embodiment, coherency may be enforced on the first network and the second network may be a relaxed order network.

Multiple independent on-chip interconnect

Techniques are disclosed relating to an I/O agent circuit of a computer system. The I/O agent circuit may receive, from a peripheral component, a set of transaction requests to perform a set of read transactions that are directed to one or more of a plurality of cache lines. The I/O agent circuit may issue, to a first memory controller circuit configured to manage access to a first one of the plurality of cache lines, a request for exclusive read ownership of the first cache line such that data of the first cache line is not cached outside of the memory and the I/O agent circuit in a valid state. The I/O agent circuit may receive exclusive read ownership of the first cache line, including receiving the data of the first cache line. The I/O agent circuit may then perform the set of read transactions with respect to the data.

I/O agent

Growing community of inventors

Sunnyvale, CA, United States of America

Per Hakan Hammarlund