ARM Standardizes Cortex Software Interface

http://www.dev-monkey.com/blogs/jon_titus.php?mid=525

 

Added on 03.26.2009 by Jon Titus
Keywords: cmsis, arm cortex, software standards

You might have missed ARM's announcement in late 2008 about the Cortex Microcontroller Software Interface Standard (CMSIS) it developed to simplify the implementation of code on specific Cortex-M-series MCUs. So far, the CMSIS comprises a Core Peripheral Access layer that defines core registers and peripherals and a Middleware Access Layer. But the latter does not yet exist within current documentation.
 
According to ARM, CMSIS defines 1. a common way to access peripheral registers and define exception vectors, 2. the register names of the Core Peripherals and the names of the Core Exception Vectors, 3. a device-independent interface for RTOS kernels (including a debug channel), and 4. interfaces for middleware components such as TCP/IP stacks and flash file systems.
 
In short, CMSIS-compliant software components let developers more easily re-use code templates and combine software components from multiple middleware vendors. The CMSIS applies--so far--to the Cortex-M0, -M1, and -M3 processors, but ARM expects the standard to apply to future Coretex-Mx-based ICs, too. 

You can learn more at the onARM Web site that offers links to the CMSIS 1.10 documents: www.onarm.com/download/download382.asp. And you will find ARM's original press announcement at: www.arm.com/news/23722.html. Lastly, the Doulos consultancy in the UK offers a "Getting started with CMSIS" tutorial that should help developers better understand how to take advantage of the CMSIS. Obtain the tutorial at: www.doulos.com/knowhow/arm/CMSIS/CMSIS_Doulos_Tutorial.pdf.
 
So far, Atmel, IAR, Luminary Micro, Micrium, NXP, SEGGER, and STMicroelectronics have jumped onto the CMSIS train.
 
If you use or plan to use an ARM Cortex-Mx-based MCU, the CMSIS might just offer a way to simplify code development and help ensure a smooth migration between other Cortes-Mx-based MCUs. --Jon Titus