Hard Processor System Technical Reference Manual: Agilex™ 5 SoCs

ID 814346
Date 4/01/2024
Public

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5.6.5.10.1.1. Signals

The following table shows the signals for the USB 3.1 controller.

Name Port I/O Description
ulpi_clk I This clock receives the 60-MHz clock supplied by the high speed ULPI PHY.
ulpi_data I/O The data input/output bus from PHY to the controller.
ulpi_dir I

This signal controls the direction of the data bus.

  • When the PHY has data to transfer to the controller, it drives ulpi_dir high to take ownership of the bus.
  • When the PHY has no data to transfer, it drives ulpi_dir low and monitors the bus,
ulpi_nxt I

Next data control

  • When the controller is sending data to the PHY, this signal indicates when the current byte is accepted by the PHY. Then the controller places the next byte on the data bus. in the following clock cycle.
  • When the PHY is sending data to the controller, this signal indicates when a new byte is available.
ulpi_stp O The controller asserts this signal for one clock cycle to indicate the end of a USB transmit packet or a register write operation and, optionally, to stop packet reception
ulpi_tx_data_en O

Output data enable

This signal is not defined in the ULPI specification. But this is used to avoid a clash between the controller and the PHY driver.