Q
What state are the port pins set to, when the device is using the factory
installed bootloader? (PSEN pulled low on reset). This does not seem to be
documented in the datasheets?
A
The port pins will be in the default Power-On state as indicated in the SFR
map, with the only exceptions of P3.0 RxD (UART Input Pin)and P3.1 TxD (UART
Output Pin).