Um....
Is it means that the default setting are:
P0 = Hi-Z
P1 ~ P3 = Output (0xFF) and configured for input?

For my second question, please look for the assembly code as shown below:

MOV P0 0xFF -- P0 = Output (0xFF)

MOV A P0 -- P0 = Input (data is depend on input port)

INC A -- P0 = Input/Output/Hi-Z??

..... others code


Since INC A instruction (or others code which are not involved any port data input/output setting, eg: DEC A, CLR A..etc) is not related to any port setting, is it (instruction) remain for the previous port setting (as the code above, P0 should be input?), or it set P0 port back to the defaut setting, which is output (or Hi-Z?)?

How about same case is happended in port 1 ~ 3??

Thank for your help!

Best regard,
Alex Au