nsx-tflite-micro

nsx-tflite-micro exposes the Helia-RT TensorFlow Lite Micro (TFLM) runtime through the NSX target nsx::tflite_micro. This repository contains the NSX adapter only; the runtime source is supplied by the required helia-rt-source module.

Public CMake contract

The module requires these values to be defined by the NSX application before it is added:

• NSX_BOARD_FLAGS_TARGET: target carrying board/compiler flags.
• NSX_SOC_FAMILY: selected NSX SoC family identifier.

It exports:

• nsx::tflite_micro: interface target containing the NSX debug-log glue and the selected Helia-RT runtime.

There is no module-owned C header or C API. Applications use the public TFLM headers supplied by the pinned Helia-RT source provider.

Configuration options

Option	Values	Default	Meaning
NSX_TFLITE_MICRO_BACKEND	reference, cmsis_nn	reference	Selects reference kernels or standard Arm CMSIS-NN kernels.
NSX_TFLITE_MICRO_VARIANT	debug, release-with-logs, release	release-with-logs	Selects Helia-RT's TFLM build profile.
TFLITE_MICRO_ROOT	filesystem path	discovered sibling	Explicit Helia-RT source tree override.
HELIA_RT_TFLM_ROOT	filesystem path	unset	Compatibility alias for TFLITE_MICRO_ROOT.
NSX_TFLITE_MICRO_CMSIS_NN_TARGET	CMake target	nsx::arm_cmsis_nn	CMSIS-NN target supplied by arm-cmsis-nn.

The adapter deliberately disables Helia's optimized helia backend. That backend remains owned by the Helia-RT NSX module and must not be enabled by this target.

Dependencies and setup

The helia-rt-source module vendors the Helia-RT checkout beside this module, so source discovery works in a normal NSX application. An explicit source override is also supported:

-DTFLITE_MICRO_ROOT=/path/to/helia-rt

The reference backend has no additional kernel dependency. For cmsis_nn, add arm-cmsis-nn before this module; it exports nsx::arm_cmsis_nn. Its source locations can be overridden with ARM_CMSIS_NN_ROOT and, when needed, ARM_CMSIS_ROOT:

-DNSX_TFLITE_MICRO_BACKEND=cmsis_nn

Supported compatibility surface

Surface	Support
Kernel backends	Reference; standard Arm CMSIS-NN
Ambiq Helia backend	Not selected by this module
NSX platform	AmbiqSuite through nsx-soc-hal
Boards and SoCs	Delegated to the selected NSX board/SoC modules
Declared toolchains	arm-none-eabi-gcc, Arm Compiler 6 (armclang), ATfE
Zephyr	Not supported by this adapter

The backend and toolchain declarations describe the supported integration surface, not a complete device-certification matrix. Device-specific qualification, operator coverage, and performance claims remain responsibilities of the pinned Helia-RT and CMSIS-NN sources. The immutable dependency identities used for the initial release are recorded in PROVENANCE.md.

Qualification scope for v0.1.0

Hosted CI uses host compilers and empty board/HAL interface targets to verify the CMake target graph, source selection, and link contract. Those jobs do not qualify a board, SoC, or production HAL.

The release preparation additionally completed these local source-build smokes:

• Arm GNU Embedded GCC: Cortex-M4 reference and CMSIS-NN archive/glue builds.
• Arm Compiler 6 (armclang): Cortex-M4 reference archive/glue build.
• Host Clang: reference and real pinned CMSIS-NN build/link smokes.

ATfE was declared in the module compatibility metadata but was not installed in the validation environment, and no physical-board or hardware-in-the-loop qualification was performed. These remain deferred before making device-level support or performance claims.

Profiling

The runtime retains Helia-RT's MicroProfilerInterface API. Consumers can use the stock TFLM MicroInterpreter integration with a profiler implementation provided by their application or by a compatible Helia Profiler release.