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FDCAN internal peripheral
- 1 Article purpose
- 2 Peripheral overview
- 3 Peripheral usage and associated software
- 4 References
1 Article purpose
The purpose of this article is to:
- briefly introduce the FDCAN 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 FDCAN peripheral.
2 Peripheral overview
FDCAN peripheral handles data communication in a Controller Area Network (CAN) bus system using message-based protocol originally designed for in-vehicle communication.
The CAN subsystem consists of two CAN modules (FDCAN1 and FDCAN2), a shared message RAM and an optional clock calibration unit.
FDCAN1 and FDCAN2 share a dedicated 10 Kbyte CAN SRAM for message transfers.
2.2 Security support
FDCAN is a non secure peripheral.
3 Peripheral usage and associated software
3.1 Boot time
The FDCAN is not used at boot time.
FDCAN instances can be allocated to:
- the Arm® Cortex®-A7 non-secure core to be controlled in Linux® by the NetDev framework (See CAN overview)
- the Arm® Cortex®-M4 to be controlled in STM32Cube MPU Package by STM32Cube FDCAN driver
3.2.2 Software frameworks
220.127.116.11 On STM32MP13x lines 
|Networking||FDCAN||Linux net/can framework|
18.104.22.168 On STM32MP15x lines 
| Networking | FDCAN | | Linux net/can framework | STM32Cube FDCAN 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 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. When the FDCAN peripheral is assigned to the Linux® OS, it is configured through the device tree according to the information given in the FDCAN device tree configuration article.
3.2.4 Peripheral assignment
22.214.171.124 On STM32MP13x lines 
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.
126.96.36.199 On STM32MP15x lines 
| rowspan="2" | Networking | rowspan="2" | FDCAN | FDCAN1 | | ☐ | ☐ | Assignment (single choice) |- | FDCAN2 | | ☐ | ☐ | Assignment (single choice) |-