blink_m33_hal Directory Reference

Directory dependency graph for blink_m33_hal:

Directories
	inc
	src

Detailed Description

The HAL-based twin of blink_m33 (#580): the Cortex-M85 releases the Cortex-M33 and sleeps, the M33 blinks LED1. Everything is identical except how the M33 drives the pin.

blink_m33 hand-rolls the combined {PODR, PDR} PCNTR1 store from a raw address cast. This app calls ra8_pcntr_set_output() instead. That primitive and its reader ra8_pcntr_read() live header-only in libs/ra8_hal, built directly on the PORT register layer with no pin-validator, logging or PFS dependency – which is what lets them compile under the M33 image's -ffreestanding build and link nothing from ra8_hal.

The primitive read-modify-writes PCNTR1, so it preserves every other pin on the port; the bare full-word store it replaces would clear the siblings. At a single-pin call site the observable LED behaviour is identical, so it is a drop-in substitute that is additionally safe on a shared port.

The primitive is host-unit-tested (tests/hal/src/test_ra8_pcntr.c), and the example's own blink step – the exact function the CPU1 loop runs – is driven against fake MMIO in tests/mocks/src/test_app_blink_m33_hal.c. Under the emulator only the primary core's ITM is echoed, so the M33 stays silent by design and LED1 is its output.