Intel® Arria® 10 Hard Processor System Technical Reference Manual

ID 683711
Date 8/28/2023
Public
Document Table of Contents

12.4.3. Memory Data Initialization

When an ECC controller is enabled, the memory data must be written first before any data read occurs. If the memory is not written, the ECC syndrome bits are random, potentially causing false single- or double-bit errors when the memory data is read.

Every byte of data in the RAM is protected with ECC. This protection can lead to spurious ECC errors under the following conditions:

  • When the MPU prefetches any uninitialized locations.
  • When the MPU (or any master) reads from an uninitialized byte.

To prevent spurious ECC errors, software must use the memory initialization block in the ECC controller to initialize the entire memory data and ECC bits. The initialization block clears the memory data. Enabling initialization in the ECC Control (CTRL) register is independent of enabling the ECC.

Note: Peripherals with true dual-port memories, such as SD/MMC, must initialize both memories explicitly.

Software controls initialization through the ECC Control (CTRL) register. This process cannot be interrupted or stopped after it starts, therefore software must wait for the initialization complete (INITCOMPLETE*) bit to be set in the Initialization Status (INITSTAT) register. Memory accesses are allowed after the initialization process is complete.

The initialization block is accessed through the register slave interface. Additionally, the Security Manager can access the initialization block. If there is an unauthorized access to the memory or a tamper attempt, the Security Manager signals the Reset Manager to begin scrambling the on-chip memories through the initialization block. After scrambling, the initialization block clears the memory data to zero. This security feature is useful in applications that require secure boot, configuration and authentication.

The Security Manager can also be configured to scramble and clear memory on a cold or warm reset, or both a cold and warm reset. This feature is configured through a combination of user fuses and configuration registers within the Security Manager.

In the Security Manager, you can also select whether the memory is cleared in series or parallel. If time savings is required, memories can be initialized in parallel. If power integrity and savings are required, memories can be initialized in series.