X9110 pdf datasheet (Dual Supp

The X9110 integrates a single digitally controlled
potentiometer (XDCP) on a monolithic CMOS integrated
circuit.
The digital controlled potentiometer is implemented using
1023 resistive elements in a series array. Between each
element are tap points connected to the wiper terminal
through switches. The position of the wiper on the array is
controlled by the user through the SPI bus interface. The
potentiometer has associated with it a volatile Wiper Counter
Register (WCR) and four non-volatile Data Registers that
can be directly written to and read by the user. The contents
of the WCR controls the position of the wiper on the resistor
array though the switches. Power-up recalls the contents of
the default data register (DR0) to the WCR.
The XDCP can be used as a three-terminal potentiometer or
as a two terminal variable resistor in a wide variety of
applications including control, parameter adjustments, and
signal processing.