This means, ST says, that embedded-system developers can be confident that they can deploy ST’s low-level drivers and abstract APIs (Application Program Interfaces) in the release version of their own firmware, allowing them to focus on their own application code rather than spending time debugging or revalidating everything down to the low-level drivers.
The HAL firmware stacks are supplied as part of the free STMCube development platform that covers all nine STM32 microcontroller series . ST’s HAL development process is modelled on CMM and the HAL development team has been externally audited to certify compliance with the internationally recognised ISO/TS16949 standard. [The Capability Maturity Model, CMM, describes how software engineering practices in an organisation evolve.]
The STM32 HALs have been subjected to unitary and functional validations, both at the firmware brick level and the system level, using validation methods specifically tailored to the STM32 microcontrollers to ensure a deeper scope of qualification than compliance with C standards alone:
- All functions are tested with all possible parameters;
- All peripheral functionalities are tested;
- System-level interactions (e.g. critical timings) between bricks are functionally tested.
The validation process covers both the pre and post-silicon phases. The HALs are first developed and verified on FPGA platforms during the microcontroller prototyping and then validated on the actual silicon. They are also tested on different tool chains (IAR, Keil, GCC) and are used by ST’s STM32CubeMX code-generation tool , which adds yet another level of functional testing.
As a result, the STM32Cube HALs offer embedded-system designers faster development and easier maintenance for their end product, with qualified, reliable, and maintained firmware packages throughout the Company’s STM32 10-year longevity commitment.