The VRC4172 has the following functions available on chip: a USB host controller, an IEEE1284 parallel controller, a 16550 serial controller, a PS/2 controller, general-purpose ports (GPIO), programmable chip select (PCS), and a PWM controller (a duty modulated light pulse generation function for LCD backlighting). The VRC4172 can be directly connected to the VR4121, allowing a reduction in the man-hours required for development of a WindowsTM CE system. Detailed function descriptions are provided in the following user's manual. Be sure to read it before designing.