Hard Processor System Technical Reference Manual: Agilex™ 5 SoCs

ID 814346
Date 4/01/2024
Public
Document Table of Contents

5.6.5.12.2. Software Resets

Software reset is an optional feature that allows the software to reset the controller and the PHY whenever it is required. This ensures that you do not have to do a hardware reset of your development platform if the driver hangs, thereby saving some time.

The GUSB2PHYCFG, GUSB3PIPECTL, and GCTL registers control the USB 2.0 PHY reset, USB3.0 PHY reset, and controller’s internal reset. Software resets must be generated in the following sequence:

  • Set GUSB2PHYCFG[31], GUSB3PIPECTL[31], and GCTL[11]. This resets the PHYs and keeps the controller in reset state.
  • Reset GUSB2PHYCFG[31] and GUSB3PIPECTL[31] after they meet PHY reset duration. This removes the reset to the PHYs.
  • Wait for the PHY clock to stabilize and reset GCTL[11] bit. This ensures that the reset to all the internal blocks are asserted when all the clocks are stable.