Understanding the Compatibility Issues
Compatibility problems between the ARM Compiler and CMSIS libraries often arise due to differences in versions, the way the libraries are linked, or the configuration parameters set in the build environment. To resolve these issues, it’s important first to understand the specific incompatibility, such as deprecated functions or misaligned versions of CMSIS with the ARM Compiler.
Ensure Compatible Versions
Before proceeding, verify compatibility between your ARM Compiler version and the CMSIS library version. Check the ARM developer documentation to ensure you're using a compatible pair. If you need to upgrade, make sure to do a comprehensive test of your firmware to catch any subtle issues a new version might introduce.
Configuration and Setup Adjustments
To address configuration-related compatibility issues, you might need to tweak project settings:
- Linker Options: Ensure the linker script is correctly set up to handle CMSIS libraries. This might involve specifying additional linker flags.
armcc --library_path /path/to/CMSIS --add_linker_script my_linker_file.ld
- Include Path Adjustments: Ensure your compiler's include path is set correctly to locate all CMSIS headers.
armcc --include_path /path/to/CMSIS/Include
Adapt to Deprecated Functions and Changes
CMSIS library updates often deprecate functions. Address these deprecations by identifying equivalent functions in the new version or adapting your code to get similar functionality. Replace deprecated function calls with updated ones as specified in the CMSIS documentation.
// Old, deprecated function
NVIC_EnableIRQ(IRQn_Type Example_IRQn);
// New function
NVIC_ClearPendingIRQ(IRQn_Type Example_IRQn);
NVIC_SetPriority(IRQn_Type Example_IRQn, PriorityGroup_Example);
Utilize Preprocessor Directives
Use preprocessor directives to manage compatibility better and support multiple versions. This method allows maintaining a single code base that adapts to various versions of CMSIS or settings.
#if defined (CMSIS_VERSION) && (CMSIS_VERSION >= 0x50000)
// Use the new API
NVIC_SetPriority(IRQn_Type Example_IRQn, PriorityGroup_Example);
#else
// Fall back on the old API
NVIC_EnableIRQ(IRQn_Type Example_IRQn);
#endif
Debugging and Testing
After making necessary code and configuration changes, thoroughly test your project to ensure functionality hasn't been compromised. Employ debugging tools, such as ARM's built-in debugger, and test on hardware whenever possible. Identifying issues early will save time and resources in the firmware development cycle.
Continuous Monitoring and Documentation
Finally, keep track of changes in both ARM Compiler and CMSIS. Subscribe to updates or newsletters from ARM and related sources for the latest news about changes that might introduce compatibility issues. Maintain internal documentation regarding your project's dependencies on specific versions of CMSIS or ARM Compilers to streamline future upgrades or maintenance.
