Each PIXI port can be configured as a general-purpose digital input (GPI) or a general-purpose digital output (GPO). The GPI threshold is adjusted by setting the DAC data register of that GPI port to the corresponding voltage. If the DAC data register is set at 0x0FFF, the GPI threshold is the DAC reference voltage. The amplitude of the input signal must be contained within 0 to AVDD. The GPI configured port can be set to detect rising edges, falling edges, either rising or falling edges, or none. When a port is configured as GPO, the amplitude of its logic-one level is set by its DAC data register. If the DAC data register is set at 0x0FFF, the GPO logic-one level is four times the DAC reference voltage. The logic-zero level is always 0 V. The host can set the logic state of GPO-configured ports through the corresponding GPO data registers.