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STM32MP15 ADC internal peripheral: Difference between revisions

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<noinclude>
{{ApplicableFor
{{ArticleBasedOnModel| [[Internal peripheral article model]]}}
|MPUs list=STM32MP15x
{{ArticleMainWriter|FabriceG}}
|MPUs checklist=STM32MP13x, STM32MP15x, STM32MP21x, STM32MP23x, STM32MP25x
{{ArticleApprovedVersion | FabriceG | NathalieS, GeraldB , ErwanLR, AnthonyN| No previous approved version | AlainF - 07Aug'18 - 8309 | 27Aug'18 }}
[[Category:Analog peripherals]]
 
{{ReviewsComments|JCT 1840: alignment needed with the last version of the model [[Internal peripheral article model]]<br>
[[Category:ToBeAlignedWithModel]]
}}
}}
</noinclude>
<noinclude></noinclude>


==Article purpose==
==Article purpose==
The purpose of this article is to
The purpose of this article is to:
* briefly introduce the ADC peripheral and its main features
* briefly introduce the ADC peripheral and its main features,
* indicate the level of security supported by this hardware block
* indicate the peripheral instances assignment at boot time and their assignment at runtime (including whether instances can be allocated to secure contexts),
* explain how each instance can be allocated to the three runtime contexts and linked to the corresponding software components
* list the software frameworks and drivers managing the peripheral,
* explain how to configure the ADC peripheral.
* explain how to configure the peripheral.


==Peripheral overview==
==Peripheral overview==
The STM32 '''ADC''' is a successive approximation analog-to-digital converter.
The '''ADC''' peripheral is a successive approximation analog-to-digital converter.


===Features===
The STM32MP15 has one ADC block with two physical ADCs:
The STM32MP15 has one ADC block with two physical ADCs:
* '''Configurable resolution''': 8, 10, 12, 14, 16 bits.
* '''Configurable resolution''': 8, 10, 12, 14, 16 bits.
Line 35: Line 29:
* Each context has its own '''configurable sequence and trigger''': software, TIM<ref name="TIM internal peripheral">[[TIM internal peripheral]]</ref>, LPTIM<ref name="LPTIM internal peripheral">[[LPTIM internal peripheral]]</ref> and EXTI<ref name="EXTI_internal_peripheral">[[EXTI internal peripheral]]</ref>.
* Each context has its own '''configurable sequence and trigger''': software, TIM<ref name="TIM internal peripheral">[[TIM internal peripheral]]</ref>, LPTIM<ref name="LPTIM internal peripheral">[[LPTIM internal peripheral]]</ref> and EXTI<ref name="EXTI_internal_peripheral">[[EXTI internal peripheral]]</ref>.


Refer to [[STM32MP15 resources#Reference manuals|STM32MP15 reference manuals]] for the complete features list, and to the software components, introduced below, to know which features are really implemented.<br>
Refer to the [[STM32MP15 resources#Reference manuals|STM32MP15 reference manuals]] for the complete list of features, and to the software frameworks and drivers, introduced below, to see which features are implemented.


===Security support===
==Peripheral usage==
The ADC is a '''non-secure''' peripheral.
This chapter is applicable in the scope of the '''OpenSTLinux BSP''' running on the Arm<sup>&reg;</sup> Cortex<sup>&reg;</sup>-A processor(s), and the '''STM32CubeMPU Package''' running on the Arm<sup>&reg;</sup> Cortex<sup>&reg;</sup>-M processor.


==Peripheral usage and associated software==
===Boot time assignment===
===Boot time===
====On {{MicroprocessorDevice | device=15}}====
The ADC is usually not used at boot time. But it may be used by the SSBL (see [[Boot chains overview]]), to check for power supplies for example.
The ADC is usually not used at boot time. But it may be used by the SSBL (see [[Boot chain overview]]), to check for power supplies for example.
 
{{#lst:STM32MP1_internal_peripherals_assignment_table_template|stm32mp1_boottime}}
===Runtime===
<section begin=stm32mp15_boottime />
====Overview====
| rowspan="1" | Analog
The ADC can be allocated to:
  | rowspan="1" | [[STM32MP15 ADC internal peripheral|ADC]]
* the Arm<sup>&reg;</sup> Cortex<sup>&reg;</sup>-A7 non-secure core to be used under Linux<sup>&reg;</sup> with [[IIO overview|IIO]] framework.
  | ADC
or
|  
* the Arm<sup>&reg;</sup> Cortex<sup>&reg;</sup>-M4 to be used with STM32Cube MPU Package with [[STM32CubeMP1 architecture|ADC HAL driver]].
|  
 
| <span title="assignable peripheral" style="font-size:21px">☐</span>
The [[#Peripheral assignment|Peripheral assignment]] chapter describes which peripheral instance can be assigned to which context.
|
 
|-
====Software frameworks====
<section end=stm32mp15_boottime />
{{:Internal_peripherals_software_table_template}}
|}
| Analog
  | [[ADC internal peripheral|ADC]]
  |  
| [[IIO overview|IIO framework]]
| [[STM32CubeMP1 architecture|STM32Cube ADC driver]]
|
|-
|}
 
====Peripheral configuration====
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.


For the Linux kernel configuration, please refer to [[ADC device tree configuration]] and [[ADC Linux driver]] articles.
===Runtime assignment===
 
====On {{MicroprocessorDevice | device=15}}====
====Peripheral assignment====
{{#lst:STM32MP1_internal_peripherals_assignment_table_template|stm32mp15_runtime}}
{{:Internal_peripherals_assignment_table_template}}
<section begin=stm32mp15_runtime />
<onlyinclude>
  | rowspan="1" | Analog
  | rowspan="1" | Analog
  | rowspan="1" | [[ADC internal peripheral|ADC]]
  | rowspan="1" | [[STM32MP15 ADC internal peripheral|ADC]]
  | ADC
  | ADC
  |  
  |
  | <span title="assignable peripheral" style="font-size:21px">☐</span>
  | <span title="assignable peripheral" style="font-size:21px">☐</span>
  | <span title="assignable peripheral" style="font-size:21px">☐</span>
  | <span title="assignable peripheral" style="font-size:21px">☐</span>
  | Assignment (single choice)
  | Assignment (single choice)
  |-
  |-
</onlyinclude>
<section end=stm32mp15_runtime />
|}
|}
 
==Software frameworks and drivers==
Below are listed the software frameworks and drivers managing the ADC peripheral for the embedded software components listed in the above tables.
 
* '''Linux<sup>&reg;</sup>''': [[IIO overview|IIO framework]]
* '''STM32Cube''': {{CodeSource | STM32CubeMP1 | Drivers/STM32MP1xx_HAL_Driver/Src/stm32mp1xx_hal_adc.c | HAL ADC driver}}
* '''U-Boot''': [[ADC_OpenSTLinux_drivers#U-Boot |U-Boot ADC driver]]
 
==How to assign and configure the peripheral==
The peripheral assignment can be done via the [[STM32CubeMX]] graphical tool (and manually completed if needed).<br />
This tool also helps to configure the peripheral:
* partial device trees (pin control and clock tree) generation for the OpenSTLinux software components,
* HAL initialization code generation for the STM32CubeMPU Package.
The configuration is applied by the firmware running in the context in which the peripheral is assigned.
 
For the Linux kernel and U-boot configuration, please refer to [[ADC device tree configuration]] article.


==How to go further==
==How to go further==
See the application note:
See application notes:
* How to get the best ADC accuracy in STM32<ref>[http://www.st.com/content/ccc/resource/technical/document/application_note/group0/3f/4c/a4/82/bd/63/4e/92/CD00211314/files/CD00211314.pdf/jcr:content/translations/en.CD00211314.pdf How to get the best ADC accuracy in STM32], by STMicroelectronics</ref>.
* How to get the best ADC accuracy in STM32<ref>[http://www.st.com/content/ccc/resource/technical/document/application_note/group0/3f/4c/a4/82/bd/63/4e/92/CD00211314/files/CD00211314.pdf/jcr:content/translations/en.CD00211314.pdf How to get the best ADC accuracy in STM32], by STMicroelectronics</ref>.
* Getting started with STM32MP15 series hardware development (AN5031)<ref>[https://www.st.com/resource/en/application_note/dm00389996.pdf Getting started with STM32MP15 series hardware development], by STMicroelectronics</ref>.<br/> It deals with analog domain power supply and reference voltage.


==References==
==References==
<references/>
<references/>
<noinclude>
[[Category:Analog peripherals|ADC internal peripheral STM32MP15]]
{{ArticleBasedOnModel| Internal peripheral article model}}
{{PublicationRequestId | 8309 | 2018-08-07 | AlainF}}
</noinclude>

Latest revision as of 17:17, 6 November 2024↑

Applicable for STM32MP15x lines


1. Article purpose[edit | edit source]↑

The purpose of this article is to:

  • briefly introduce the ADC peripheral and its main features,
  • indicate the peripheral instances assignment at boot time and their assignment at runtime (including whether instances can be allocated to secure contexts),
  • list the software frameworks and drivers managing the peripheral,
  • explain how to configure the peripheral.

2. Peripheral overview[edit | edit source]↑

The ADC peripheral is a successive approximation analog-to-digital converter.

The STM32MP15 has one ADC block with two physical ADCs:

  • Configurable resolution: 8, 10, 12, 14, 16 bits.
  • Each ADC has up to 20 multiplexed channels (including 6 internal channels connected only to ADC2).
  • The conversions can be performed in single, continuous, scan or discontinuous mode.
  • The result can be read in a left- or right-aligned 32-bit data register by using CPU or DMA[1].
  • The analog watchdog feature allows the application to detect if the input voltage goes beyond the user-defined, high or low thresholds.
  • A common input clock for the two ADCs, which can be selected between 2 different clock[2] sources (Synchronous or Asynchronous clock).
  • The common reference voltage can be provided by either VREFBUF[3] or any other external regulator[4] wired to VREF+ pin.

Each ADC supports two contexts to manage conversions:

  • Regular conversions can be done in sequence, running in background
  • Injected conversions have higher priority, and so have the ability to interrupt the regular sequence (either triggered in SW or HW). The regular sequence is resumed, in case it has been interrupted.
  • Each context has its own configurable sequence and trigger: software, TIM[5], LPTIM[6] and EXTI[7].

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

3. Peripheral usage[edit | edit source]↑

This chapter is applicable in the scope of the OpenSTLinux BSP running on the Arm® Cortex®-A processor(s), and the STM32CubeMPU Package running on the Arm® Cortex®-M processor.

3.1. Boot time assignment[edit | edit source]↑

3.1.1. On STM32MP15x lines More info.png[edit | edit source]↑

The ADC is usually not used at boot time. But it may be used by the SSBL (see Boot chain overview), to check for power supplies for example.

Click on How to.png to expand or collapse the legend...

Domain Peripheral Boot time allocation Comment How to.png
Instance Cortex-A7
secure
(ROM code) 		Cortex-A7
secure
(TF-A BL2) 		Cortex-A7
non-secure
(U-Boot)
Analog ADC ADC ☐

3.2. Runtime assignment[edit | edit source]↑

3.2.1. On STM32MP15x lines More info.png[edit | edit source]↑

Click on How to.png to expand or collapse the legend...

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

(STM32Cube)
Analog ADC ADC ☐ ☐ Assignment (single choice)

4. Software frameworks and drivers[edit | edit source]↑

Below are listed the software frameworks and drivers managing the ADC peripheral for the embedded software components listed in the above tables.

5. How to assign and configure the peripheral[edit | edit source]↑

The peripheral assignment can be done via the STM32CubeMX graphical tool (and manually completed if needed).
This tool also helps to configure the peripheral:

  • partial device trees (pin control and clock tree) generation for the OpenSTLinux software components,
  • HAL initialization code generation for the STM32CubeMPU Package.

The configuration is applied by the firmware running in the context in which the peripheral is assigned.

For the Linux kernel and U-boot configuration, please refer to ADC device tree configuration article.

6. How to go further[edit | edit source]↑

See application notes:

  • How to get the best ADC accuracy in STM32[8].
  • Getting started with STM32MP15 series hardware development (AN5031)[9].
    It deals with analog domain power supply and reference voltage.

7. References[edit | edit source]↑

  1. ↑ DMA internal peripheral
  2. ↑ RCC internal peripheral
  3. ↑ VREFBUF internal peripheral
  4. ↑ Regulator overview
  5. ↑ TIM internal peripheral
  6. ↑ LPTIM internal peripheral
  7. ↑ EXTI internal peripheral
  8. ↑ How to get the best ADC accuracy in STM32, by STMicroelectronics
  9. ↑ Getting started with STM32MP15 series hardware development, by STMicroelectronics

Template:ArticleBasedOnModel


Analog-to-digital converter. The process of converting a sampled analog signal to a digital code that represents the amplitude of the original signal sample.

Central processing unit

Direct memory access

Voltage reference buffer (STM32 specific)

Low-power timer (STM32 specific)

External interrupt

Board support package

Arm® is a registered trademark of Arm Limited (or its subsidiaries) in the US and/or elsewhere. Arm logo.png

Cortex®

Second stage boot loader

Read only memory

Trusted firmware for Arm® Cortex®-A

Boot loader stage 2

Das U-Boot -- the universal boot loader (see U-Boot)

Open portable trusted execution environment

Linux® is a registered trademark of Linus Torvalds.

Hardware abstraction layer

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