公开(公告)号：US20210326169A1

公开(公告)日：2021-10-21

申请号：US16852107

申请日：2020-04-17

Applicant: Apple Inc.

Inventor： Nachiappan Chidambaram Nachiappan ,  Matthew R. Johnson ,  Vinodh R. Cuppu

IPC: G06F9/46 ,  G06F9/48

Abstract: Systems, apparatuses, and methods for controlling bandwidth through shared transaction limits are described. An apparatus includes at least a plurality of agents, a plurality of transaction-limit (T-Limit) nodes, a T-Limit manager, and one or more endpoints. The T-Limit manager creates a plurality of credits for the plurality of agents to send transactions to a given endpoint. Then, the T-Limit manager partitions the credits into N+1 portions for N agents, wherein the extra N+1 portion is a shared pool for use by agents when they run out of their private credits. The T-Limit manager assigns a separate private portion of the N portions to the N agents for use by only the corresponding agent. When an agent runs out of private credits, the agent's T-Limit node sends a request to the T-Limit manager for credits from the shared pool.

公开(公告)号：US10972408B1

公开(公告)日：2021-04-06

申请号：US16786581

申请日：2020-02-10

Applicant: Apple Inc.

Inventor： Nachiappan Chidambaram Nachiappan ,  Vinodh R. Cuppu

IPC: G06F13/364 ,  H04L12/937 ,  H04L12/863 ,  G06F13/362 ,  G06F13/374

Abstract: Systems, apparatuses, and methods for implementing a configurable packet arbiter with minimum progress guarantees are described. An arbiter includes at least control logic, a plurality of counters, and a tunables matrix. The tunables matrix stores values for a plurality of configurable parameters for the various transaction sources of the arbiter. These parameter values determine the settings that the arbiter uses for performing arbitration. One of the parameters is a minimum progress guarantee value that specifies how many times each source should be picked per interval. The minimum progress guarantee helps to reduce arbitration-related jitter. Also, the arbiter includes a grant counter for each source. After the minimum progress guarantees are satisfied, the arbiter selects the source with the lowest grant counter among the sources with packets eligible for arbitration. Then, the arbiter increments the grant counter of the winning source by a grant increment amount specific to the source.

公开(公告)号：US10423558B1

公开(公告)日：2019-09-24

申请号：US16058433

申请日：2018-08-08

Applicant: Apple Inc.

Inventor： Shawn Munetoshi Fukami ,  Yiu Chun Tse ,  David L. Trawick ,  Hengsheng Geng ,  Jaideep Dastidar ,  Vinodh R. Cuppu ,  Deniz Balkan

IPC: G06F3/06 ,  G06F13/40 ,  G06F13/16 ,  G06F13/362 ,  G06F9/54 ,  G06F13/18

Abstract: A system and method for efficiently routing data in a communication fabric. A computing system includes a fabric for routing data among one or more agents and a memory controller for system memory. The fabric includes multiple hierarchical clusters with a split topology where the data links are physically separated from the control links. A given cluster receives a write command and associated write data, and stores them in respective buffers. The given cluster marks the write command as a candidate to be issued to the memory controller when it is determined the write data will arrive ahead of the write command at the memory controller after being issued. The given cluster prevents the write command from becoming a candidate to be issued when it is determined the write data may not arrive ahead of the write command at the memory controller.