Intel® Arria® 10 Hard Processor System Technical Reference Manual

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

7.1.3.4. Reset Manager

To avoid unsecure snooping of RAM contents, the Security Manager can send signals to the Reset Manager to clear all RAM on a cold or warm reset.

These signals are the result of fuse programming combined with the configuration bits found in the HPS_Swoptset and HPS_secopt1 register in the Security Manager.

In addition, the fuse information that determines whether the RAMs are cleared in series or parallel is also sent to the Reset Manager. Clearing the memory in series prevents a power spike that could occur with parallel clearing of RAM. The policies for how or when security states take affect can be programmed in the HPS_secopt1 register. Refer to the "Security State" section for more information.

The RAM instances that are cleared during a warm or cold reset are:

  • On-chip RAM
  • USB0
  • USB1
  • SD/MMC
  • EMAC0 RX and TX buffer
  • EMAC1 RX and TX buffer
  • EMAC2 RX and TX buffer
  • DMA
  • NAND read data, write data, and ECC RAMs
  • QSPI
  • MPU RAM

If a tamper event occurs, the Security Manager notifies the Reset Manager and the following sequence occurs:

  1. All domain resets are asserted.
  2. All RAMs are cleared.
  3. The Reset Manager enters a dead state waiting for a POR release from Security Manager. All cold reset sources except Security Manager are ignored.

When FPGA POR and HPS POR are asserted, the Security Manager goes into reset.