supports one USB device address with three endpoints. The SIE allows the USB host to communicate with the function integrated
into the microcontroller. A 3.3V regulated output pin provides a pull-up source for the external USB resistor on the D– pin.
The USB D+ and D– USB pins can alternately be used as PS/2 SCLK and SDATA signals, so that products can be designed to
respond to either USB or PS/2 modes of operation. PS/2 operation is supported with internal pull-up resistors on SCLK and
SDATA, the ability to disable the regulator output pin, and an interrupt to signal the start of PS/2 activity. No external components
are necessary for dual USB and PS/2 systems, and no GPIO pins need to be dedicated to switching between modes. Slow edge
rates operate in both modes to reduce EMI.