Hard Processor System Technical Reference Manual: Agilex™ 5 SoCs

ID 814346
Date 11/27/2024
Public
Document Table of Contents

5.5.7.1. Initialization Procedure

After the POR, the PHY is designed (along with the controller) to complete initialization with the connected device (device identification) in an extended read mode. In this mode, the controller asserts the RE# signal for a long time to guarantee correct data capture. The controller requires notification that the PHY is fully initialized, and for this, the PHY asserts the dfi_init_complete signal. This indicates that the PHY and memory devices are ready to accept commands.

The procedure to initialize the combo PHY is as follows:

  1. Assert the softphy_rst_n signal by driving it to ’b0. All programmable registers are cleared and set to their default values.
  2. De-assert the softphy_rst_n signal to ’b1.
  3. Finish the Flash device initialization and any basic operations that are required. All transactions to and from the device are carried out in extended read/write modes. This guarantees successful operations although with low performance.
  4. Assert the dll_rst_n signal by driving it to 'b0. The clocks to the PHY now can be changed. If a change in the NAND ONFI mode is needed during the initialization, this is when that change is performed.
  5. Program all the PHY registers.
  6. De-assert the dll_rst_n signal (to ’b1). This signal is re-synchronized within each slice so there are no specific requirements for its de-assertion.
  7. The PHY slice’s primary DLLs locks and then the PHY asserts the dfi_init_complete signal. This indicates that the PHY and memory devices are ready to accept commands.
  8. The PHY is now ready for normal traffic.

The following figure shows a waveform that describes the PHY initialization flow.

Figure 167. Waveform of Initialization Procedure