1. Article purpose
The purpose of this article is to
- briefly introduce the TIM 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 how to configure the TIM peripheral
2. Peripheral overview
The TIM peripheral is a multi-channel timer unit, available in various configurations, depending on the instance used. There are basically following categories: advanced-control timers, general-purpose timers and basic timers.
The TIM can provide: PWM with complementary output and dead-time insertion, break detection, input capture[1], quadrature encoder[2] interface (typically used for rotary encoders), trigger source for other internal peripherals like: ADC[3], DFSDM[4]. The full list can be found in Peripherals Interconnect matrix in the reference manual.
2.1. Features
The TIM peripheral is available in different configurations, depending on the selected instance :
- TIM1 and TIM8 are advanced-control timers, with 6 independent channels.
- TIM2, TIM3, TIM4 and TIM5 are general-purpose timers, with 4 independent channels.
- TIM12, TIM13 and TIM14 are general-purpose timers, with 2 (TIM12) or 1 (TIM13 and TIM14) independent channels.
- TIM15, TIM16 and TIM17 are also general-purpose timers, with 2 (TIM15) or 1 (TIM16 and TIM17) independent channels. Compare to TIM12, TIM13 and TIM14, this configuration brings some features that are very useful for motor control (like break function, DMA burst mode control, complementary output with dead-time insertion, ...)
- TIM6 and TIM7 are basic timers
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
2.2.1. On STM32MP13x lines 
There are 14 instances of TIM:
- TIM instances 1, 2, 3, 4, 5, 6, 7 and 8 are non-secure peripheral
- TIM instances 12, 13, 14, 15, 16 and 17 are secure (under ETZPC control)
2.2.2. On STM32MP15x lines
The 14 instances of TIM are non-secure peripherals.
3. Peripheral usage and associated software
3.1. Boot time
The TIM is not used at boot time.
3.2. Runtime
3.2.1. Overview
3.2.1.1. On STM32MP13x lines
TIM12 and/or TIM15 can be allocated to:
- the Arm® Cortex®-A7 secure core to be controlled in the secure monitor (OP-TEE), to perform HSI and CSI calibrations[5] in RCC.
TIM13, TIM14, TIM16 and TIM17 can also be allocated to the Arm® Cortex®-A7 secure context, but there is no support for them in OP-TEE yet.
All TIM instances can be allocated to:
- the Arm® Cortex®-A7 non-secure to be controlled in Linux® by the PWM, the IIO, and/or the Counter frameworks.
3.2.1.2. On STM32MP15x lines
TIM12 and/or TIM15 can be allocated to:
- the Arm® Cortex®-A7 secure core to be controlled in the secure monitor (TF-A or OP-TEE), to perform HSI and CSI calibrations[5] in RCC.
All TIM instances can be allocated to:
- the Arm® Cortex®-A7 non-secure to be controlled in Linux® by the PWM, the IIO, and/or the Counter frameworks.
or
- the Arm® Cortex®-M4 to be controlled in STM32Cube MPU Package by TIM HAL driver
3.2.2. Software frameworks
3.2.2.1. On STM32MP13x lines
| Domain | Peripheral | Software components | Comment | |
|---|---|---|---|---|
| OP-TEE | Linux | |||
| Core/Timers | TIM | OP-TEE TIM driver | PWM framework IIO framework, Counter framework |
|
3.2.2.2. On STM32MP15x lines
| Domain | Peripheral | Software components | Comment | ||
|---|---|---|---|---|---|
| OP-TEE | Linux | STM32Cube | |||
| Core/Timers | TIM | TF-A TIM driver OP-TEE TIM driver |
PWM framework IIO framework, Counter framework |
STM32Cube TIM driver | |
3.2.3. 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 Linux kernel configuration, please refer to TIM device tree configuration and TIM Linux driver articles.
3.2.4. Peripheral assignment
3.2.4.1. On STM32MP13x lines
Click on the right to expand the legend...
| Domain | Peripheral | Runtime allocation | Comment | ||
|---|---|---|---|---|---|
| Instance | Cortex-A7 secure (OP-TEE) |
Cortex-A7 non-secure (Linux) | |||
| Core/Timers | TIM | TIM1 (APB2 group) | ☐ | ||
| TIM2 (APB1 group) | ☐ | ||||
| TIM3 (APB1 group) | ☐ | ||||
| TIM4 (APB1 group) | ☐ | ||||
| TIM5 (APB1 group) | ☐ | ||||
| TIM6 (APB1 group) | ☐ | ||||
| TIM7 (APB1 group) | ☐ | ||||
| TIM8 (APB2 group) | ☐ | ||||
| TIM12 (APB6 group) | ☐ | ☐ | Assignment (single choice) TIM12 or TIM15 can be used for HSI/CSI calibration[5] | ||
| TIM13 (APB6 group) | ⬚ | ☐ | Assignment (single choice) | ||
| TIM14 (APB6 group) | ⬚ | ☐ | Assignment (single choice) | ||
| TIM15 (APB6 group) | ☐ | ☐ | Assignment (single choice) TIM12 or TIM15 can be used for HSI/CSI calibration[5] | ||
| TIM16 (APB6 group) | ⬚ | ☐ | Assignment (single choice) | ||
| TIM17 (APB6 group) | ⬚ | ☐ | Assignment (single choice) | ||
3.2.4.2. On STM32MP15x lines
Click on the right to expand the legend...
| Domain | Peripheral | Runtime allocation | Comment | |||
|---|---|---|---|---|---|---|
| Instance | Cortex-A7 secure (OP-TEE) |
Cortex-A7 non-secure (Linux) |
Cortex-M4 (STM32Cube) | |||
| Core/Timers | TIM | TIM1 (APB2 group) | ☐ | ☐ | Assignment (single choice) | |
| TIM2 (APB1 group) | ☐ | ☐ | Assignment (single choice) | |||
| TIM3 (APB1 group) | ☐ | ☐ | Assignment (single choice) | |||
| TIM4 (APB1 group) | ☐ | ☐ | Assignment (single choice) | |||
| TIM5 (APB1 group) | ☐ | ☐ | Assignment (single choice) | |||
| TIM6 (APB1 group) | ☐ | ☐ | Assignment (single choice) | |||
| TIM7 (APB1 group) | ☐ | ☐ | Assignment (single choice) | |||
| TIM8 (APB2 group) | ☐ | ☐ | Assignment (single choice) | |||
| TIM12 (APB1 group) | ☐ | ☐ | ☐ | Assignment (single choice) TIM12 or TIM15 can be used for HSI/CSI calibration[5] | ||
| TIM13 (APB1 group) | ☐ | ☐ | Assignment (single choice) | |||
| TIM14 (APB1 group) | ☐ | ☐ | Assignment (single choice) | |||
| TIM15 (APB2 group) | ☐ | ☐ | ☐ | Assignment (single choice) TIM12 or TIM15 can be used for HSI/CSI calibration[5] | ||
| TIM16 (APB2 group) | ☐ | ☐ | Assignment (single choice) | |||
| TIM17 (APB2 group) | ☐ | ☐ | Assignment (single choice) | |||
4. How to go further
STM32 cross-series timer overview[7] application note.
5. References