Posted on December 18, 2014 at 11:40Yet another bug / gotcha with the SPL...
FLASH_OB_GetUser() shifts the User option bits right 20 bits, which means that if you try to compare against the OB_IWDG_SW/HW, OB_STOP_RST or OB_STDBY_RST constants, you'll never get a comparison match.
The workaround for this one is to do an additional shift of 4 bits before comparing:
// Make sure the IWDG watchdog is enabled on startup
if (((FLASH_OB_GetUser() << 4) & OB_IWDG_SW) == OB_IWDG_SW) {
printf(''OptionBytes: IWDG not enabled, updating...\n'');
// Unlock option bytes and set IWDG, Reset-on-STOP and Reset-on-Standby
FLASH_OB_Unlock();
FLASH_OB_UserConfig(OB_IWDG_HW, OB_STOP_RST, OB_STDBY_RST);
FLASH_OB_Launch();
}
