ARM group seeks to extend microcontroller software reuse

MUNICH, Germany — Processor intellectual property licensor ARM Holdings plc (Cambridge, England) came to a hotel adjacent to the Electronica exhibition here and announced the availability of the Cortex Microcontroller Software Interface Standard (CMSIS), a hardware abstraction layer for the Cortex-M processor series.

A number of microcontroller vendors and development tools suppliers have worked with ARM to develop the standard; specifically Atmel, IAR Systems, Luminary Micro, Micrium, NXP, Segger and STMicroelectronics. The initiative is expected to open the re-use of third-party software in embedded applications on Cortex-M3 processor-based microcontrollers.

Reinhard Keil, director of MCU Tools for ARM, said the CMSIS group was now open to other companies.

The idea behind the CMSIS is that it should enable consistent, simple software interfaces for silicon and middeware providers, simplify software re-use and reduce effort for microcontroller developers. The interface is expected to simplify migration of existing software to Cortex processor-based microcontrollers.

Keil said that while the standard and its roadmap were being disclosed now, Keil would be launching CMSIS-compliant development tools at the Embedded World exhibition in the first quarter of 2009. Jean Anne Booth, chief marketing officer of Luminary Micro asserted that Luminary would be compliant in the first quarter of 2009.

The standard has been designed to be scalable from the smallest 8-Kbyte Cortex-M3 microcontrollers up to devices with communication peripherals such as Ethernet or USB-OTG. The CMSIS memory requirement for the Core Peripheral Access Layer is less than 1-Kbyte of code and less than 10 bytes of RAM.

"The Cortex Microcontroller Software Interface Standard provides a common approach to interface peripherals, real-time operating systems, and middleware components which benefits silicon vendors and developers alike," said Reinhard Keil, director of MCU Tools for ARM, in a statement. ARM said it plans to extend the CMSIS with a Middleware Access Layer that provides standard software interfaces for Ethernet, SD/MMC, and a debug interface for consistent kernel-aware debugging of RTOS kernels. This extension to the CMSIS will simplify the deployment of standard middleware components on Cortex processor-based microcontrollers.

Provided as a set of comprehensive documentation that is designed for integration into device user’s guides, the CMSIS is available for free download from www.onarm.com, a website providing a comprehensive resource for embedded developers. CMSIS documentation and maintenance of the software layer will be provided by ARM, the company said.