Hard Processor System Technical Reference Manual: Agilex™ 5 SoCs

ID 814346
Date 7/19/2024
Public
Document Table of Contents

4.1.3. CCU Features

The cache coherency unit provides the following features:
  • Coherency directory to track the state of the caches in Arm DSU
  • Snoop filter support
  • Single-bit error correction and double-bit error detection (SECDED) in the coherency directory
  • Support for distributed virtual memory (DVM) using the ARM Advanced Microcontroller Bus Architecture (AMBA) Advanced eXtensible Interface (AXI) Coherency Extensions, also known as the ACE protocol. The CCU sends distributed virtual memory broadcast messages to the DSU and the TCU in the SMMU.
  • Quality of service (QoS) support for transaction prioritization using a weight bandwidth allocation algorithm
  • Interrupt support for CCU errors
  • Support for both coherent and non-coherent transactions
  • 2 x 32 KB of system memory cache (SMC) to enable CHI-B atomic operations
  • Support for interleaving accesses to SDRAM, resulting in improved performance