USBPHYC internal peripheral

Applicable for STM32MP13x lines, STM32MP15x lines

1 Article purpose[edit]

The purpose of this article is to

  • briefly introduce the USBPHYC peripheral and its main features
  • indicate the level of security supported by this hardware block
  • explain how each instance can be allocated to the runtime contexts and linked to the corresponding software components
  • explain, when necessary, how to configure the USBPHYC peripheral.

2 Peripheral overview[edit]

The USBPHYC peripheral is a block that contains a dual port USB high-speed UTMI+ PHY and a UTMI switch. It makes the interface between:

  • the internal USB controllers (USBH and OTG)
  • the external USB physical lines (DP, DM)

2.1 Features[edit]

The USBPHYC peripheral:

  • controls a two port high-speed PHY:
    • Port1 connected to the USBH controller
    • Port2 connected via the UTMI+switch to the USBH or to the OTG controller
  • sets the PLL values
  • performs other controls (and monitoring) on the PHY.

USBPHYC.png

Refer to STM32MP13 reference manuals or STM32MP15 reference manuals for the complete list of features, and to the software components, introduced below, to see which features are implemented.

2.2 Security support[edit]

2.2.1 On STM32MP13x lines Warning.png[edit]

The USBPHYC is a secure programmable peripheral (under ETZPC control).

2.2.2 On STM32MP15x lines More info.png[edit]

The USBPHYC peripheral is a non-secure peripheral.

3 Peripheral usage and associated software[edit]

3.1 Boot time[edit]

USBPHYC instances are boot devices that support Flash programming with STM32CubeProgrammer.

The USBPHYC peripheral is used by ROM code, FSBL and SSBL when using OTG in Device mode (DFU).

3.2 Runtime[edit]

3.2.1 Overview[edit]

The USBPHYC peripheral can be allocated to the the Arm® Cortex®-A7 non-secure core to be used under Linux® with PHY framework.

The peripheral assignment chapter describes which peripheral instance can be assigned to which context.

3.2.2 Software frameworks[edit]

3.2.2.1 On STM32MP13x lines Warning.png[edit]
Domain Peripheral Software components Comment
OP-TEE Linux
High-speed interface USBPHYC (USB HS PHY controller) Linux PHY framework
3.2.2.2 On STM32MP15x lines More info.png[edit]
Domain Peripheral Software components Comment
OP-TEE Linux STM32Cube
High-speed interface USBPHYC (USB HS PHY controller) Linux PHY framework

3.2.3 Peripheral configuration[edit]

The configuration is applied by the firmware running in the context to which the peripheral is assigned. The configuration can be done alone via the STM32CubeMX tool for all internal peripherals, and then manually completed (particularly for external peripherals) according to the information given in the corresponding software framework article.

For Linux kernel configuration, please refer to USBPHYC device tree configuration.

3.2.4 Peripheral assignment[edit]

3.2.4.1 On STM32MP13x lines Warning.png[edit]
STM32MP13IPsOverview.png

Check boxes illustrate the possible peripheral allocations supported by STM32 MPU Embedded Software:

  • means that the peripheral can be assigned () to the given runtime context.
  • means that the peripheral can be assigned to the given runtime context, but this configuration is not supported in STM32 MPU Embedded Software distribution.
  • is used for system peripherals that cannot be unchecked because they are statically connected in the device.

Refer to How to assign an internal peripheral to a runtime context for more information on how to assign peripherals manually or via STM32CubeMX.
The present chapter describes STMicroelectronics recommendations or choice of implementation. Additional possiblities might be described in STM32MP13 reference manuals.

Domain Peripheral Runtime allocation Comment
Instance Cortex-A7
secure
(OP-TEE)
Cortex-A7
non-secure
(Linux)
High speed interface USBPHYC (USB HS PHY controller) USBPHYC (USB HS PHY controller) Assignment (single choice)
3.2.4.2 On STM32MP15x lines More info.png[edit]
STM32MP15 internal peripherals

Check boxes illustrate the possible peripheral allocations supported by STM32 MPU Embedded Software:

  • means that the peripheral can be assigned () to the given runtime context.
  • means that the peripheral can be assigned to the given runtime context, but this configuration is not supported in STM32 MPU Embedded Software distribution.
  • is used for system peripherals that cannot be unchecked because they are statically connected in the device.

Refer to How to assign an internal peripheral to a runtime context for more information on how to assign peripherals manually or via STM32CubeMX.
The present chapter describes STMicroelectronics recommendations or choice of implementation. Additional possiblities might be described in STM32MP15 reference manuals.

Domain Peripheral Runtime allocation Comment
Instance Cortex-A7
secure
(OP-TEE)
Cortex-A7
non-secure
(Linux)
Cortex-M4

(STM32Cube)
High speed interface USBPHYC (USB HS PHY controller) USBPHYC (USB HS PHY controller)