AN 763: Intel® Arria® 10 SoC Device Design Guidelines

ID 683192
Date 5/17/2022
Public
Document Table of Contents

5.1.12.3. ECC for L2 Cache Data Memory

The L2 cache memory is ECC protected, while the tag RAMs are parity protected. L2 cache ECC is enabled through a control register in the System Manager.

Note: For details on the L2 cache ECC Controller, refer to the following sections of the Arria 10 Hard Processor System Technical Reference Manual, Chapter 9: Cortex-A9 Microprocessor Unit Subsystem: "Single Event Upset Protection" under the L2 Cache section, and "L2 Cache Controller Address Map for Arria 10" under the Cortex-A9 MPU System Complex Register Implementation section.

GUIDELINE: The L1 and L2 cache must be configured as write-back and write-allocate for any cacheable memory region with ECC enabled.

For BSPs supported through the Intel SoC EDS, you can configure your BSP for ECC support with the bsp-editor utility. For bare-metal firmware, refer to the Arria 10 Hard Processor System Technical Reference Manual, chapter on Cortex-A9 Microprocessor Unit Subsystem, L2 Cache Controller Address Map for Arria 10 section.

GUIDELINE: Cache-coherent accesses through the L3 interconnect using the ACP must perform 64-bit wide, 64-bit aligned write accesses when ECC is enabled in the L2 Cache Controller.

Enabling ECC does not affect the performance of the L2 cache, but accesses using the ACP must be 64-bit wide, 64-bit aligned in memory. This includes FPGA masters accessing the ACP over the FPGA-to-HPS Bridge. Refer to the Arria 10 Hard Processor System Technical Reference Manual, chapter covering HPS-FPGA Bridges, FPGA-to-HPS Access to ACP section, Table 8-3 for a list of possible combinations of bridge width and FPGA master width, alignment and burst size and length.