Apple Inc.

Oracle International Corporation

Chandan Shantharaj

Fnu Rajeev Kumar

Sandeep Kumar Gupta

Sahil Kapoor

Brian P Lilly

Mridul Agarwal

Tyler J Huberty

Eric Jason Furbish

Peter G Soderquist

Vivek Venkatraman

Krishna C Potnuru

Stephen G Meier

Yanran Yang

Mamata Godthi

Claire Shih

An apparatus includes a cache memory circuit, a prefetcher circuit, and a prefetch deny list circuit, including a plurality of entries, may be included. The cache memory circuit may be configured to store information retrieved from a lower-level memory. The prefetcher circuit may be configured to generate a prefetch request for a particular prefetch address. The prefetch deny list circuit may be configured to allocate, in response to an indication from the cache memory circuit that a previously prefetched address went unused, a given entry, of the plurality of entries, for the previously prefetched address. The prefetch deny list circuit may be further configured to determine whether a particular address for a particular prefetch request corresponds to an active one of the plurality of entries. In response to a determination that a particular active entry corresponds to the particular address, prefetch deny list circuit may deny the particular prefetch request.

Deny list for a memory prefetcher circuit

An Integrated Circuit (IC) includes a storage element and control circuitry. The control circuitry is configured to select, responsively to a scan-enable control, between a functional-data input and a scan-data input to serve as an input to the storage element, to selectively disable toggling of an output of the storage element, responsively to a clock-enable control, by gating a clock signal provided to the storage element, and, while the clock-enable control indicates that the output of the storage element is to be disabled from toggling, to select the input of the storage element to be the scan-data input.

Data gating using scan enable pin

A variable latency cache memory is disclosed. A cache subsystem includes a pipeline control circuit configured to initiate cache memory accesses for data. The cache subsystem further includes a cache memory circuit having a data array arranged into a plurality of groups, wherein different ones of the plurality of groups have different minimum access latencies due to different distances from the pipeline control circuit. A plurality of latency control circuits configured to ensure a latency is bounded to a maximum value for a given access to the data array, wherein a given latency control circuit is associated with a corresponding group of the plurality of groups. The latency for a given access may thus vary between a minimum access latency for a group closest to the pipeline control circuit to a maximum latency for an access to the group furthest from the pipeline control circuit.

Variable hit latency cache

A method for designing an integrated circuit. The method may include obtaining a register-transfer level (RTL) file for the integrated circuit. The RTL file may include hardware description language code that describes various modules for the integrated circuit. The method may further include selecting, within the RTL file, various state elements having a predetermined clock skew. The method may further include associating, in response to selecting the state elements, the state elements with a predetermined clock header. The method may further include generating a gate-level netlist using the RTL file. The state elements may be assigned to the predetermined clock header in the gate-level netlist. The method may further include generating, using the gate-level netlist, a clock network for the integrated circuit. The state elements in the clock network may have the predetermined clock skew.

Reducing clock skew in synthesized modules

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San Jose, CA, United States of America

Chandan Shantharaj