Patent ID: 11900146
Assignee: APPLE INC.
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 14:
15. A system comprising:
a plurality of agents configured to generate memory access requests, wherein the memory access requests include real-time requests and non-real-time requests;
a memory subsystem including a memory and a memory controller configured to receive the memory access requests from ones of the plurality of agents, wherein the memory controller includes:
a non-real-time transaction table configured to store incoming non-real-time requests received from ones of the plurality of agents;
a non-real-time selection circuit configured to select ones of the non-real-time requests from the non-real-time transaction table;
a real-time transaction table configured to store, separately from the non-real-time requests, incoming real-time requests; and
a real-time selection circuit configured to select ones of the real-time requests from the real-time transaction table;
a processor transaction table configured to store incoming memory access requests received from one or more processors;
a graphics transaction table configured to store incoming memory access requests received from one or more graphics processing units; and
an arbitration circuit configured to select a memory request from among memory access requests stored in the real-time and non-real-time transaction tables, the processor transaction table, and the graphics transaction table, wherein the arbitration circuit is configured to perform a credit-based arbitration, and wherein the non-real-time transaction table, the processor transaction table, and the graphics transaction table share a first pool of credits, and wherein a second pool of credits is reserved exclusively to the real-time transaction table;

wherein the memory controller is configured to, in response to the arbitration circuit selecting a particular memory access request, execute the particular memory access request in the memory subsystem.