The principle of a basic I/O port expander is that it
provides additional I/Os that can be used by the host processor to implement additional features such as increased number of inputs/outputs,
expanding the number of control signals and
mixed signal lines.
controlling a greater number of peripherals without resorting to an
additional Complex Programmable Logic Device (CPLD) or upgrading the
central processing unit (CPU).
Xpander logic include an advanced
matrix keypad
controller supporting up to 96 keys and an
advanced PWM controller
providing complex brightness pattern control.
The Xpander home page is
here.
