CMSIS-Driver specifies generic driver interfaces for peripherals commonly used in embedded systems with Arm® Cortex® processors.

User applications and middleware components can control such peripherals using the CMSIS-Driver API and so achieve better code reuse and simpler integration in various ecosystems. The API is designed to be generic and independent of a specific RTOS making it reusable across a wide range of supported microcontroller devices.

The following block diagram shows an exemplary set up for various drivers.

Example use of CMSIS-Drivers with Middleware

The standard CMSIS-Driver interfaces connect microcontroller peripherals with middleware that implements communication stacks, file system and graphic user interfaces.

Benefits

Using CMSIS-Driver provides great benefits to the embedded developers and software vendors:

The CMSIS-Driver API covers many common peripherals present in modern embedded systems for sensor interaction, data storage, communication and graphics.
The unified API follows the similar design principles across all peripherals. This reduces learning efforts and increases developers' productivity. See Theory of Operation for details.
Driver templates files provide code sceletons that help to get started with implementations for specific peripherals. See CMSIS-Driver Files.
Support for multiple driver instances with Access Struct.
Driver-Validation Suite provides a set of tests to verify compatibility to CMSIS-Driver API definitions.

Covered Interfaces

CMSIS-Driver APIs are defined for the following driver interfaces:

CAN: Interface to CAN bus peripheral.
Ethernet: Interface to Ethernet MAC and PHY peripheral.
I2C: Multi-master Serial Single-Ended Bus interface driver.
MCI: Memory Card Interface for SD/MMC memory.
NAND: NAND Flash Memory interface driver.
Flash: Flash Memory interface driver.
SAI: Serial audio interface driver (I2s, PCM, AC'97, TDM, MSB/LSB Justified).
SPI: Serial Peripheral Interface Bus driver.
Storage: Storage device interface driver.
USART: Universal Synchronous and Asynchronous Receiver/Transmitter interface driver.
USB: Interface driver for USB Host and USB Device communication.
GPIO: General-purpose Input/Output driver.
VIO: API for virtual I/Os (VIO).
WiFi: Interface driver for wireless communication.

A list of current CMSIS-Driver implementations is available here.

Access to CMSIS-Driver

CMSIS-Driver intefaces are actively maintained in the CMSIS 6 GitHub repository and released as part of the CMSIS Software Pack.

The CMSIS Software Pack publishes the API Interface under the Component Class CMSIS Driver with header files and a documentation. These header files are the reference for the implementation of the standardized peripheral driver interfaces.

These implementations are published typically in the Device Family Pack of a related microcontroller family under the Component Class CMSIS Driver. A Device Family Pack may contain additional interfaces in the Component Class Device to extend the standard Peripheral Drivers covered by this CMSIS-Driver specification with additional device specific interfaces for example for Memory BUS, GPIO, or DMA.

The following directories and files relevant to CMSIS-Driver are present in the ARM::CMSIS Pack:

Directory	Content
📂 CMSIS	CMSIS Base software components folder
┣ 📂 Documentation/html/Driver	A local copy of this CMSIS-Driver documentation
┣ 📂 Driver	Directory with CMSIS-Driver component, see CMSIS-Driver Files
┣ 📂 DriverTemplates	Driver Template files (Driver_interface.c)
┣ 📂 Include	API header files (Driver_interface.h, Driver_Common.h)
┗ 📂 VIO	Implementation of virtual Input/Output interface (VIO)