Infinite Reset Problem - Option Bytes

Background of the problem：

The mass-produced board has an infinite reset of the board, and it will work normally if it is replaced with a chip that has been programmed before.

For the hardware test, it is found that the reset pin has a reset pulse every 500ms, but it has been confirmed that the watchdog is not used.

It's strange, is there a problem with this batch of chips?

After careful investigation, it is found that if the STlink uility is used to burn, the option byte WDG_SW is not checked-that is, the hardware watchdog is turned on by mistake, causing the chip to reset infinitely.

Check the manual, WDG_SW is set to 1 by default to enable the software watchdog, and the software watchdog requires software code to enable it; setting it to 0 means to enable the hardware watchdog, which leads to infinite resets.

ST_LINK uility configuration：