VSS33VDD32VSS31BOOT030PB729PB628PB527PB426PA1425VDDIO224PA1323PA1222PA1121PA1020PA919PA818VDD17VSS16PB115PB014PA713PA612PA511PA410PA39PA28PA17PA06VDDA5VSSA4NRST3PC15-OSC32_OUT2PC14-OSC32_IN1