<Li> Ports do not have handshake or interrupt capability . </Li> <Li> With 4 ports, 16 different combinations of I / O are possible . </Li> <P>' Latched' means the bits are put into a storage register (array of flip - flops) which holds its output constant even if the inputs change after being latched . </P> <P> The 8255's outputs are latched to hold the last data written to them . This is required because the data only stays on the bus for one cycle . So, without latching, the outputs would become invalid as soon as the write cycle finishes . </P>

The port that is used for the generation of handshake lines in mode 1 or mode 2 is