Sifive, Inc.

Henry Cook

Wesley Waylon Terpstra

John Ingalls

Derek E Pappas

Yunsup Lee

Ryan Macdonald

Richard Xia

Mark Nugent

Pin Hung Chen

Megan Anneke Wachs

Eric Andrew Gouldey

Michael Klinglesmith

Leigang Kou

Ernest L Edgar

Robert P Adler

Perrine Peresse

Abderrahmane Sensaoui

Dean Liberty

Derek Pappas

A method and apparatus for a speculative request indicator is described. A method includes providing, for a cache hierarchy, a messaging protocol used for transfer operations among agents in the cache hierarchy, the messaging protocol indicating acceptable cache coherency states for a cache block indicated in a request message and providing, in the messaging protocol for selection by an agent, a speculative request indicator when sending the request message, wherein the speculative request indicator differentiates between a demand request and a speculative request with respect to the cache block.

Speculative request indicator in request message

A method for managing orders of operations between one or more clients and one or more servers is disclosed. The method includes partitioning addressable regions of logical servers on or within an interconnect link into multiple regions including a first orderable region, and providing logical client an ability to push ordering responsibility within the first orderable region to a server. Over the first orderable region, two request messages for access to memory-mapped sources including two respective operations are transmitted, and the two request messages originate from a same logical client. The ordering responsibility can include a first rule for order of operations between the two request messages.

Orderability of operations

An integrated circuit for translating and reverse-translating the address included in a memory request is disclosed. The integrated circuit may first comprise a processor, a first boundary function, a second boundary function, and a component device. The processor is configured to transmit a memory request to a target module over a bus of the integrated circuit. The memory request requests access to one or more memory mapped resources and the memory request includes a physical address. The first boundary function is configured to translate the physical address to a relative address which operates in or applies to a different address space than an address space that the physical address operates in or applies to. The second boundary function is configured to translate the relative address to the physical address. The device is configured utilize the physical address transmitted by the second boundary function.

Address boundary functions for physical and localized addresses

Described are methods and a system for atomic memory operations with contended cache lines. A processing system includes at least two cores, each core having a local cache, and a lower level cache in communication with each local cache. One local cache configured to request a cache line to execute an atomic memory operation (AMO) instruction, receive the cache line via the lower level cache, receive a probe downgrade due to other local cache requesting the cache line prior to execution of the AMO, and send the AMO instruction to the lower level cache for remote execution in response to the probe downgrade.

Method for executing atomic memory operations when contested

Systems and methods are disclosed for automated generation of integrated circuit designs and associated data. These allow the design of processors and SoCs by a single, non-expert who understands high-level requirements; allow the en masse exploration of the design-space through the generation processors across the design-space via simulation, or emulation; allow the easy integration of IP cores from multiple third parties into an SoC; allow for delivery of a multi-tenant service for producing processors and SoCs that are customized while also being pre-verified and delivered with a complete set of developer tools, documentation and related outputs. Some embodiments, provide direct delivery, or delivery into a cloud hosting environment, of finished integrated circuits embodying the processors and SoCs.

Integrated circuits as a service

Described is a data cache implementing hybrid writebacks and writethroughs. A processing system includes a memory, a memory controller, and a processor. The processor includes a data cache including cache lines, a write buffer, and a store queue. The store queue writes data to a hit cache line and an allocated entry in the write buffer when the hit cache line is initially in at least a shared coherence state, resulting in the hit cache line being in a shared coherence state with data and the allocated entry being in a modified coherence state with data. The write buffer requests and the memory controller upgrades the hit cache line to a modified coherence state with data based on tracked coherence states. The write buffer retires the data upon upgrade. The data cache writebacks the data to memory for a defined event.

Data cache with hybrid writeback and writethrough

Systems and methods are disclosed for generation and testing of integrated circuit designs with point-to-point connections between modules. These may allow for the rapid design and testing (e.g. silicon testing) of processors and SoCs. For example, type parameterization may be used to generate point-to-point connections in a flexible manner. For example, a point-to-point connection between the source module and the sink module that includes one or more named wires specified by bundle type may be automatically generated based on using the bundle type as a type parameterization input. For example, these system and methods may be used to rapidly connect a custom processor design, including one or more IP cores, to a standard input/output shell for a SoC design to facilitate rapid silicon testing of the custom processor design.

Point-to-point module connection interface for integrated circuit generation

Systems and methods are disclosed for generation and testing of integrated circuit designs with clock crossings between clock domains and reset crossings between reset domains. These may allow for the rapid design and testing (e.g. silicon testing) of processors and SoCs. Clock crossings may be automatically generated between modules, inferring the values of design parameters, such as a signaling protocol (e.g. a bus protocol), directionality, and/or a clock crossing type (e.g., synchronous, rational divider, or asynchronous), of a clock crossing. Reset crossings may be automatically generated in a similar manner. For example, implicit classes may be used to generate clock crossings or reset crossings in a flexible manner. For example, these system and methods may be used to rapidly connect a custom processor design, including one or more IP cores, to a standard input/output shell for a SoC design to facilitate rapid silicon testing of the custom processor design.

Growing community of inventors

Berkeley, CA, United States of America

Henry Cook