I am currently working on one of my projects for which I need to make 60 output lines out of port0 of c51(these outputs r to the LED’S at various traffic signals). the 60 output can be multiplexed to just 18 lines for which I select 8255.(port A,B &C of 8255 can serve my purpose ).simultaneously I want to make any one port of c51 as an input port tht constantly monitors (i.e reads with he help of sensors )the traffic density & interrupts the normal routine as traffic density exceeds the average count.i am using 20 sensors according to my need for which ill be needing 8255 again now shall I dedicate port 1 for it or can I use same port 0 .since in future I ve to do serial communication so I cant use port3 now n I have put port 2 for address decoding so saving port 1 will be a great benefit for me plz tell me is there any way to use same port of c51 as input /output at the same time .hopefully someone can help me out .
thnx
munaza