STM32F0 WWDG driver causes immediate reset on init

[AlexLanzano]

Summary

The STM32F0 WWDG driver (src/watchdog/stm32f0_wwdg.c) triggers an immediate system reset when whal_Watchdog_Init is called on the STM32F091. The IWDG driver works correctly on the same board.

Observed behavior

• Calling whal_Watchdog_Init starts the WWDG, but the system resets before the first whal_Watchdog_Refresh can be called
• Adding debug prints inside Init (UART output) delays execution enough that Init completes and a few refreshes succeed — suggesting a timing-sensitive issue
• With debug prints, reading CR after each step shows T6=1 throughout Init
• Without debug prints, the reset is immediate and consistent
• Tested with both whal_Reg_Update (read-modify-write) and whal_Reg_Write (direct write) for the CR register — same behavior
• Matched ST HAL approach (WRITE_REG(CR, WDGA | counter) for both Init and Refresh) — same behavior

Configuration

• Board: NUCLEO-F091RC (STM32F091CC)
• SYSCLK: 48 MHz (PLL: HSI/2 × 12)
• WWDG config: prescaler=3 (/8), window=0x7F, counter=0x7F
• Max WWDG timeout at 48 MHz PCLK: ~44ms
• WWDG clock enabled during Board_Init (counter free-runs before test starts)