DESCRIPTION
The SC84520 Scrolling Mouse Controller id specially designed to control serial mouse or PS/2 mouse device. This single chip can interface three key-switched and 4 X-Y photo-couples plus Z-axis directly plus Z-axis directly to RS-232C or 8042 controller. There are four types Z-axis inputs used to implement scrolling mouse functionality.

FEATURES
*Using 50kΩ±1% resistor for RC oscillation
*Compatible with legacy PS/2 mouse
*Compatible with Microsoft serial scrolling mouse
*Compatible with Microsoft PS/2 scrolling mouse
*Serial or PS/2 port auto-detect
*100 bytes PnP ID code could be filled by code layer
*Built-in noise immunity circuit
*The sampling rate of motion detector is up to 65 kHz
*Built-in three zener diodes : one in VDDto VSS,twoinRTStoVDD
*CMOS push-pull RXD output
*Built-in current comparator for photo-couples input
*Built-in three step dynamic input impedance
*Three key-switches and four photo-coupled inputs
*RTS debouncing circuit include
*Photo couple test mode include
*Low power dissipation
*Six types Z direction input:
1. Photo couples input (Z/1)
2. Key-switches input
3. Voltage-sensing input
4. Mechanical input(Z/1)
5. Photo couples input (Z/4)
6. Mechanical input (Z/2)