#SCPS133IMG1020 shows an application in which the TCA6424A can be used.
A. Device address configured as
0100000 for this example.
B. P00 and P02–P10 are configured as
inputs.
C. P01, P11–P17, and P20–P27 are
configured as outputs.
D. Resistors are required for inputs
(on P port) that may float. If a driver to an input will not let the input
float, a resistor is not needed. Outputs (in the P port) do not need pullup
resistors.