Hello everyone,

I've seen in many books and some programs (with comments) that when you write 0xFF to a port, the port is configured to be an input port. I really did not understand this...If it becomes an input port (is it the same input as 8255 ports become upon setting the appropriate control word?) then how do we output data on it?? please clarify if we can configure the 8051 ports to do a single task like input or output only.(I dont think so).
Also, I've read, the ports are LATCHED and sometimes the value you read from the latch may not be equal to the value at the pin (i've read this line from THE 8051 Architecture, Programming and Applications by Kenneth J. Ayala ). Can anyone brief me on this too..
Warm Regards,
Sriharsha.