CMSIS-Core (Cortex-M)  Version 5.2.1
CMSIS-Core support for Cortex-M processor-based devices
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CMSIS-Core Device Templates

Arm supplies CMSIS-Core device template files for the all supported Cortex-M processors and various compiler vendors. Refer to the list of Tested and Verified Toolchains for compliance.

These CMSIS-Core device template files include the following:

  • Register names of the Core Peripherals and names of the Core Exception Vectors.
  • Functions to access core peripherals, special CPU instructions and SIMD instructions (for Cortex-M4 and Cortex-M7)
  • Generic startup code and system configuration code.

The detailed file structure of the CMSIS-Core device templates is shown in the following picture.

CMSIS_CORE_Files.png
CMSIS-Core File Structure

CMSIS-Core Processor Files

The CMSIS-Core processor files provided by Arm are in the directory .\CMSIS\Core\Include. These header files define all processor specific attributes do not need any modifications. The core_<cpu>.h defines the core peripherals and provides helper functions that access the core registers. One file is available for each supported Cortex-M processor:

Header File Processor
core_cm0.h for the Cortex-M0 processor
core_cm0plus.h for the Cortex-M0+ processor
core_cm3.h for the Cortex-M3 processor
core_cm4.h for the Cortex-M4 processor
core_cm7.h for the Cortex-M7 processor
core_cm23.h for the Cortex-M23 processor
core_cm33.h for the Cortex-M33 processor
core_cm35p.h for the Cortex-M35P processor
core_sc000.h for the SecurCore SC000 processor
core_sc300.h for the SecurCore SC300 processor
core_armv8mbl.h for the Armv8-M Baseline processor
core_armv8mml.h for the Armv8-M Mainline processor

Device Examples

The CMSIS Software Pack defines several devices that are based on the various processors. The device related CMSIS-Core files are in the directory .\Device\ARM and include CMSIS-Core processor file explained before. The following sample devices are defined in the CMSIS-Pack description file ARM.CMSIS.pdsc:

Family Device Description
ARM Cortex-M0 ARMCM0 Cortex-M0 based device
ARM Cortex-M0 plus ARMCM0P Cortex-M0+ based device
ARM Cortex-M3 ARMCM3 Cortex-M3 based device
ARM Cortex-M4 ARMCM4 Cortex-M4 based device without floating-point hardware
ARM Cortex-M4 ARMCM4_FP Cortex-M4 based device with floating-point hardware
ARM Cortex-M7 ARMCM7 Cortex-M4 based device without floating-point hardware
ARM Cortex-M7 ARMCM7_FP Cortex-M7 based device with single precision floating-point unit (FPU)
ARM Cortex-M7 ARMCM7_DP Cortex-M7 based device with double precision floating-point unit
ARM Cortex-M7 ARMCM7 Cortex-M7 based device without floating-point hardware
ARM Cortex-M23 ARMCM23 Cortex-M23 based device without TrustZone
ARM Cortex-M23 ARMCM23_TZ Cortex-M23 based device with TrustZone
ARM Cortex-M33 ARMCM33 Cortex-M33 based device without TrustZone, SIMD, FPU
ARM Cortex-M33 ARMCM33_TZ Cortex-M33 based device with TrustZone, no SIMD, no FPU
ARM Cortex-M33 ARMCM33_DSP_FP Cortex-M33 based device with SIMD, FPU, no TrustZone
ARM Cortex-M33 ARMCM33_DSP_FP_TZ Cortex-M33 based device with TrustZone, SIMD, FPU
ARM Cortex-M35P ARMCM35P Cortex-M35P based device without TrustZone, SIMD, FPU
ARM Cortex-M35P ARMCM35P_TZ Cortex-M35P based device with TrustZone, no SIMD, no FPU
ARM Cortex-M35P ARMCM35P_DSP_FP Cortex-M35P based device with SIMD, FPU, no TrustZone
ARM Cortex-M35P ARMCM35P_DSP_FP_TZ Cortex-M35P based device with TrustZone, SIMD, FPU
ARM SC000 ARM SC000 SC000 based device
ARM SC300 ARM SC300 SC300 based device
ARMv8-M Baseline ARMv8MBL Armv8-M Baseline based device with TrustZone
ARMv8-M Mainline ARMv8MML Armv8-M Mainline based device with TrustZone
ARMv8-M Mainline ARMv8MML_DP Armv8-M Mainline based device with TrustZone and double precision FPU
ARMv8-M Mainline ARMv8MML_SP Armv8-M Mainline based device with TrustZone and single precision FPU
ARMv8-M Mainline ARMv8MML_DSP Armv8-M Mainline based device with TrustZone and SIMD
ARMv8-M Mainline ARMv8MML_DSP_DP Armv8-M Mainline based device with TrustZone, SIMD, and double precision FPU
ARMv8-M Mainline ARMv8MML_DSP_SP Armv8-M Mainline based device with TrustZone, SIMD, and single precision FPU

Template Files

To simplify the creation of CMSIS-Core device files, the following template files are provided that should be extended by the silicon vendor to reflect the actual device and device peripherals. Silicon vendors add to these template files the following information:

  • Device Peripheral Access Layer that provides definitions for device-specific peripherals.
  • Access Functions for Peripherals (optional) that provides additional helper functions to access device-specific peripherals.
  • Interrupt vectors in the startup file that are device specific.
Template File Description
.\Device\_Template_Vendor\Vendor\Device\Source\ARM\startup_Device.s Startup file template for Arm C/C++ Compiler.
.\Device\_Template_Vendor\Vendor\Device\Source\GCC\startup_Device.s Startup file template for GNU GCC Arm Embedded Compiler.
.\Device\_Template_Vendor\Vendor\Device\Source\IAR\startup_Device.s Startup file template for IAR C/C++ Compiler.
.\Device\_Template_Vendor\Vendor\Device\Source\system_Device.c Generic system_Device.c file for system configuration (i.e. processor clock and memory bus system).
.\Device\_Template_Vendor\Vendor\Device\Include\Device.h Generic device header file. Needs to be extended with the device-specific peripheral registers. Optionally functions that access the peripherals can be part of that file.
.\Device\_Template_Vendor\Vendor\Device\Include\system_Device.h Generic system device configuration include file.

Adapt Template Files to a Device

The following steps describe how to adopt the template files to a specific device or device family. Copy the complete all files in the template directory and replace:

  • directory name 'Vendor' with the abbreviation for the device vendor e.g.: NXP.
  • directory name 'Device' with the specific device name e.g.: LPC17xx.
  • in the file names 'Device' with the specific device name e.g.: LPC17xx.

Each template file contains comments that start with ToDo: that describe a required modification. The template files contain place holders:

Placeholder Replaced with
<Device> the specific device name or device family name; i.e. LPC17xx.
<DeviceInterrupt> a specific interrupt name of the device; i.e. TIM1 for Timer 1.
<DeviceAbbreviation> short name or abbreviation of the device family; i.e. LPC.
Cortex-M# the specific Cortex-M processor name; i.e. Cortex-M3.

The device configuration of the template files is described in detail on the following pages: