公开(公告)号：US20230169003A1

公开(公告)日：2023-06-01

申请号：US18160575

申请日：2023-01-27

Applicant: Apple Inc.

Inventor： James Vash ,  Gaurav Garg ,  Brian P. Lilly ,  Ramesh B. Gunna ,  Steven R. Hutsell ,  Lital Levy-Rubin ,  Per H. Hammarlund ,  Harshavardhan Kaushikkar

IPC: G06F12/0815 ,  G06F12/0831

CPC classification number: G06F12/0815 ,  G06F12/0831 ,  G06F2212/1032

Abstract: 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.

公开(公告)号：US20230056044A1

公开(公告)日：2023-02-23

申请号：US17821296

申请日：2022-08-22

Applicant: Apple Inc.

Inventor： Per H. Hammarlund ,  Lior Zimet ,  James Vash ,  Gaurav Garg ,  Sergio Kolor ,  Harshavardhan Kaushikkar ,  Ramesh B. Gunna ,  Steven R. Hutsell

IPC: G06F13/28 ,  G06F12/0815 ,  G06F12/109

Abstract: 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.