FMC internal peripheral

1 Article purpose[edit]

The purpose of this article is to

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

2 Peripheral overview[edit]

The FMC peripheral is used to interface an STM32 MPU with SLC 8-bit or 16-bit NAND Flash memory devices.
The FMC NAND controller supports:

  • Programmable error correction capability (ECC) using BCH8 code, BCH4 code or Hamming code
  • Programmable page size of 2048, 4096 and 8192 bytes
  • Programmable memory timings
  • Multiple dice per package.

2.1 Features[edit]

Refer to 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]

The FMC is a non-secure peripheral.

3 Peripheral usage and associated software[edit]

3.1 Boot time[edit]

FMC instance is boot device that support serial boot for Flash programming with STM32CubeProgrammer.

3.2 Runtime[edit]

3.2.1 Overview[edit]

The FMC instance can be allocated to the Arm® Cortex®-A7 non-secure core to be controlled in Linux® by the MTD framework

Chapter #Peripheral assignment describes which instance can be assigned to which context.

3.2.2 Software frameworks[edit]

Domain Peripheral Software frameworks Comment
Cortex-A7
secure
(OP-TEE)
Cortex-A7
non-secure
(Linux)
Cortex-M4

(STM32Cube)
Mass storage FMC Linux MTD 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 FMC device tree configuration

3.2.4 Peripheral assignment[edit]

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.
  • 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)
Mass storage FMC FMC

4 How to go further[edit]

5 References[edit]