Mcu — Requirements

Normative

Defines what a conformant MCU driver MUST do. Keywords per Requirement Keywords; conformance per Conformance. Requirements do not carry individual status — the set-level status applies to all of them. Signatures, error codes, and configuration properties are in the API Reference, Errors, and Configuration Reference pages. Cross-module rules (types, error model, naming, memory mapping) are in General.

Mandatory (MUST) - 13 Requirements

The conformance contract — an implementation MUST satisfy every requirement here.

State machine and lifecycle

CHI-MCU-MUST-01 — State machine

After reset the driver MUST be in MCU_DRV_STATE_UNINIT. Mcu_Init MUST move it to MCU_DRV_STATE_INIT. The driver is single-instance and has no de-initialization.

CHI-MCU-MUST-02 — Initialization

Mcu_Init MUST initialize the driver and the core hardware registers assigned to it (mode-relevant registers, reset management, and registers affecting multiple peripherals) — but not the clock setup (Mcu_InitClock) nor I/O pins. configPtr MUST be NULL_PTR.

CHI-MCU-MUST-03 — Reset-reason capture at initialization

Where the hardware supports reset-reason detection, Mcu_Init MUST obtain the reset reason from the hardware, hold it in an internal variable, and then clear it from the hardware.

Clock management

CHI-MCU-MUST-04 — Clock initialization

Mcu_InitClock MUST apply the MCU-specific clock configuration identified by clockId (enable/disable, frequency/divider, stabilisation, and distribution settings), returning E_OK if accepted or E_NOT_OK otherwise.

CHI-MCU-MUST-05 — Non-blocking clock stabilisation

Mcu_InitClock MUST return without busy-waiting for clock stabilisation. Where stabilisation requires polling a status register, that MUST be handled by Mcu_PollFunction (a short fixed delay MAY instead be handled within Mcu_InitClock).

CHI-MCU-MUST-06 — Clock distribution status

Mcu_IsClockDistributed MUST return TRUE once every clock set by Mcu_InitClock has stabilised and been distributed, and FALSE otherwise. Called before Mcu_Init — or after a reset before Mcu_InitClock — it MUST return TRUE.

CHI-MCU-MUST-07 — Event polling

Mcu_PollFunction MUST check and handle McuDrv events — clock stabilisation, distribution after stabilisation, and any configured clock supervision.

CHI-MCU-MUST-08 — Clock failure reporting

On a detected clock failure (typically during Mcu_InitClock, Mcu_PollFunction, or a supporting interrupt) the driver MUST report MCU_RTERR_CLOCK via LogM_Report at runtime-error level (CHI-GEN-MUST-10).

Reset

CHI-MCU-MUST-09 — Reset-reason query

Mcu_GetResetRawValue MUST return the reset reason captured by Mcu_Init as a bitwise-ORed uint32. Called before Mcu_Init it MUST return 0.

CHI-MCU-MUST-10 — Perform reset

Mcu_PerformReset MUST perform a microcontroller reset using a hardware feature. The caller is responsible for ensuring no preemption during the call.

Errors, types, and configuration

CHI-MCU-MUST-11 — Development error detection

When development error reporting is enabled, each API MUST detect the conditions listed in Errors and report them via LogM_Report (CHI-GEN-MUST-10).

CHI-MCU-MUST-12 — Public types and error identifiers

The driver MUST provide Mcu_ConfigType, Mcu_ClockIdType, the reset-reason values, and the development and runtime error identifiers as defined in API Reference and Errors, and MUST use the shared type system from General (CHI-GEN-MUST-09).

CHI-MCU-MUST-13 — Configuration model

The driver MUST support the configuration model in Configuration Reference — a General section and a ConfigSet with a non-empty clock_settings list addressable by clockId — following the common model in General (CHI-GEN-MUST-12).