Stratix® 10 Hard Processor System Technical Reference Manual

ID 683222
Date 8/15/2024
Public
Document Table of Contents

4.4. CCU System Integration

Figure 8. Cache Coherency Unit Integration Within System

The coherency interconnect in the CCU accepts both coherent and non-coherent transactions from masters in the system. The coherency interconnect routes non-coherent transactions to the appropriate target. Coherent transactions are initially routed to either the CCC or the IOCB in the CCU.

All accesses from the Cortex* -A53 MPCore are routed through the CCU so the coherency directory can be updated. TCU and FPGA-to-HPS bridge accesses and peripheral master accesses coming from the L3 interconnect are routed to the CCU if they are cacheable. Non-cacheable accesses route directly to the slave.

Note: As part of the SMMU, translation buffer units (TBUs) sit between the master peripherals and the L3 interconnect. The FPGA-to-HPS bridge interface also passes through a TBU before interfacing with the CCU. The system TCU manages the TBUs and performs page table walks on translation misses. A DVM interface on the TCU allows the Cortex*-A53 MPCore processor to send TLB control information to the TCU.

For more information about TBUs and distributed virtual memory support, refer to the "Distributed Virtual Memory Controller" section.

The CCU interfaces with the L3 interconnect and the SDRAM L3 interconnect . The SDRAM L3 interconnect provides a 64-bit register bus interface to the CCU for accessing the L3 SDRAM adapter, L3 SDRAM scheduler and hard memory controller registers. The CCU accesses external memory through a 128 -bit interface to the SDRAM L3 interconnect .