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 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_cm55.h	for the Cortex-M55 processor
core_cm85.h	for the Cortex-M85 processor
core_starmc1.h	for the STAR-MC1 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
core_armv81mml.h	for the Armv8.1-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 Cortex-M55	ARMCM55	Cortex-M55 based device with TrustZone, SIMD, double precision FPU, and floating-point MVE
ARM Cortex-M85	ARMCM85	Cortex-M85 based device with TrustZone, PACBTI, SIMD, double precision FPU, and floating-point MVE
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
ARMv8.1-M Mainline	ARMv81MML_DSP_DP_MVE_FP	Armv8.1-M Mainline based device with TrustZone, SIMD, double precision FPU, and floating-point MVE

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_ac5_noSct.s	Startup file template for Arm Compiler V5. No linker description file necessary. Deprecated
.\Device\_Template_Vendor\Vendor\Device\Source\ARM\startup_Device_ac5.s	Startup file template for Arm Compiler V5. Use of linker description file is necessary. Deprecated
.\Device\_Template_Vendor\Vendor\Device\Source\ARM\startup_Device_ac6.S	Preprocessed startup file template for Arm Compiler V6. Use of linker description file is necessary. Deprecated
.\Device\_Template_Vendor\Vendor\Device\Source\ARM\Device_ac5.sct	Linker description file for Arm Compiler V5. Deprecated
.\Device\_Template_Vendor\Vendor\Device\Source\ARM\Device_ac6.sct	Linker description file for Arm Compiler V6.
.\Device\_Template_Vendor\Vendor\Device\Source\GCC\startup_Device.S	Preprocessed startup file template for GNU GCC Arm Embedded Compiler. Use of linker description file is necessary.<. Deprecated
.\Device\_Template_Vendor\Vendor\Device\Source\GCC\gcc_arm.ld	Linker description file 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\startup_Device.c	Generic startup_Device.c file for device startup implemented in C. Use of linker description file is necessary.
.\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: