Hard Processor System Technical Reference Manual: Agilex™ 5 SoCs

ID 814346
Date 7/19/2024
Public

A newer version of this document is available. Customers should click here to go to the newest version.

Document Table of Contents

5.5.7.3. DLL Secondary Delay Configuration

Depending on the DLL operation mode, the values written in the phy_dll_slave_ctrl_reg register will have a different meaning in terms of time delay calculation as described below.

Table 232.  DLL Secondary Delay Operation Mode Values
DLL Operation mode Lock Mode Total Delay Notes
Bypass mode N/A DLLDly * (reg_value+1) N/A
Normal operation Full clock mode Tclk_phy*(reg_value+1)/256 Delay was a resolution of 1/256 of clock period.

Half clock mode

Tclk_phy*(reg_value+1)/256

reg_value must be lower than 128. This means that the maximum delay is equal to half clock cycle.
Saturation mode DLLDly * (reg_value+1) Same as bypass mode. This case is typical for low values of PHY clock frequency.
Where:
  • DLLDly: Delay of a single delay element.
  • reg_val: 8-bit value stored in read_dqs_delay, read_dqs_cmd_delay, clk_wr_delay or clk_wrdqs_delay.
  • Tclk_phy: Period of PHY clock.