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IAR Embedded Workbench for Arm 9.70.x

Library Configuration

In this section:

The Library Configuration options determine which library to use.

LibConfigTab_04_ARM.png

For information about the runtime library, library configurations, the runtime environment they provide, and the possible customizations, see The DLIB runtime environment.

Configuration file

Displays the library configuration file that will be used. A library configuration file is chosen automatically depending on the project settings. If you have chosen Custom DLIB in the Library drop-down list, you must specify your own library configuration file.

Enable thread support in library

Select this option to automatically configure the runtime library for use with threads.

Library low-level interface implementation

Controls the type of low-level interface for I/O to be included in the library.

For Cortex-M, choose between:

None

No low-level support for I/O available in the libraries. You must provide your own __write function to use the I/O functions part of the library.

Semihosted, stdout/stderr via semihosting

Semihosted I/O which uses the BKPT instruction.

Semihosted, stdout/stderr via SWO

Semihosted I/O which uses the BKPT instruction for all functions except for the stdout and stderr output where the SWO interface is used. This means a much faster mechanism where the application does not need to halt execution to transfer data.

IAR breakpoint

Not available.

For other cores, choose between:

None

No low-level support for I/O available in the libraries. You must provide your own __write function to use the I/O functions part of the library.

Semihosted

Semihosted I/O which uses the SVC instruction (earlier SWI).

IAR breakpoint

The IAR proprietary variant of semihosting, which does not use the SVC instruction and, therefore, does not need to set a breakpoint on the SVC vector. This is an advantage for applications which require the SVC vector for their own use, for example an RTOS. This method can also lead to performance improvements. However, this method does not work with applications, libraries, and object files that are built using tools from other vendors.

CMSIS

To enable CMSIS support, use these options:

Use CMSIS

Adds the CMSIS header files to the compiler include path.

Note that if your application source code includes CMSIS header files explicitly, then you should not use this option. This option is only available for Cortex-M devices.

DSP library

Links your application with the CMSIS DSP library. This option is only available for Cortex-M devices.