1. Article purpose[edit source]
The purpose of this article is to
- briefly introduce the HDP peripheral (hardware debug port) 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 needed, how to configure the HDP peripheral.
2. Peripheral overview[edit source]
The HDP peripheral is used to output some internal signals on up to 8 GPIO pins.
Follow the sequence below to connect a GPIO to an internal signal via the HDP:
- First of all, look for the internal signal you want to monitor in the HDP signal multiplexing table of the STM32MP13 reference manuals or STM32MP15 reference manuals:
- Search for the HDP signal on which you can get it among eight possible choices.
- Note the corresponding HDPx multiplexing value to select.
- Then, look for the most suitable GPIO pin on which you can output HDPx (in the datasheets for STM32MP13x lines
and datasheets for STM32MP15x lines ):
The GPIO bank, pin, alternate function and HDPx multiplexing value are the information required to configure each HDP signal.
2.1. Features[edit source]
Refer to STM32MP13 reference manuals or STM32MP15 reference manuals for the complete list of features, and to the software components, introduced below, to know which features are really implemented.
2.2. Security support[edit source]
The HDP is a non-secure peripheral.
3. Peripheral usage and associated software[edit source]
3.1. Boot time[edit source]
The HDP is not used at boot time.
3.2. Runtime[edit source]
3.2.1. Overview[edit source]
The HDP can be allocated to the Arm® Cortex®-A7 non-secure core to be used under Linux® HDP driver.
3.2.2. Software frameworks[edit source]
3.2.2.1. On STM32MP13x lines [edit source]
| Domain | Peripheral | Software components | Comment | |
|---|---|---|---|---|
| OP-TEE | Linux | |||
| Trace & Debug | HDP | HDP Linux driver | ||
3.2.2.2. On STM32MP15x lines [edit source]
| Domain | Peripheral | Software components | Comment | ||
|---|---|---|---|---|---|
| OP-TEE | Linux | STM32Cube | |||
| Trace & Debug | HDP | HDP Linux driver | |||
3.2.3. Peripheral configuration[edit source]
The configuration is applied by the firmware running in the context to which the peripheral is assigned. The configuration by itself can be performed via the STM32CubeMX tool for all internal peripherals. It can then be manually completed (especially for external peripherals) according to the information given in the corresponding software framework article.
3.2.4. Peripheral assignment[edit source]
3.2.4.1. On STM32MP13x lines [edit source]
Click on the right to expand the legend...
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) | |||
| Trace & Debug | HDP | HDP | ☐ | ||
3.2.4.2. On STM32MP15x lines [edit source]
Click on the right to expand the legend...
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) | |||
| Trace & Debug | HDP | HDP | ☐ | |||
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Arm® is a registered trademark of Arm Limited (or its subsidiaries) in the US and/or elsewhere. 
Arm® is a registered trademark of Arm Limited (or its subsidiaries) in the US and/or elsewhere.