DESCRIPTION
The µPD31172 (commercial name: VRC4172) is a companion chip designed for NEC’s µPD30121 microprocessor (commercial name: VR4121).
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 Windows™ CE system.

FEATURES
• Directly connectable to VR4121
• On-chip USB host controller
   • USB ports: 2
   • Compliant with the USB OpenHCI specifications, release 1.0
   • Communicates with USB device asynchronously with host CPU
   • Full-speed (12 Mbps) and low-speed (1.5 Mbps) modes supported
   • System clock: 48 MHz
• On-chip PS/2 controller
• On-chip IEEE1284 parallel controller
• On-chip 16550 serial controller
• General-purpose ports (GPIO): 24
• On-chip PWM controller
   • Duty modulated light pulse generation function for LCD backlighting
• Internal maximum operating frequency: 48 MHz
• Power supply voltage: VDD = 3.3 V ± 0.3 V
• Package: 208-pin plastic FBGA

APPLICATIONS
• Battery-driven portable information devices
• Peripheral devices for PCs, etc.