GENERAL DESCRIPTION
Zilog’s Z8E520 (OTP) and Z8C520 (Masked ROM) microcontrollers are low-power Z8Plus MCUs, designed for the cost-effective implementation of USB and multiprotocol pointing devices.
   
FEATURES   
■ Six Vectored Interrupts with Fixed Priority
■ Processor Speed Dividable by Firmware Control
■ Operating Current: 5 mA typical in USB Mode; 2.5 mA
    typical in Serial Mode (@ 3 MHz); 5 mA typical in PS/2
    Mode
■ 16 Total Input/Output Pins (Open-Drain/Push-Pull)
    Configurable
■ 6 inputs with 3 level Programmable Reference
    Comparators
■ 16-Bit Programmable Watch-Dog Timer (WDT) with
    Internal RC Oscillator
■ Software Programmable Timers Configurable as:
    – Two 8-Bit Standard Timers and One 16-Bit
        Standard Timer or
    – One 16-Bit Standard Timer and One 16-Bit Pulse
        Width Modulator (PWM) Timer
■ Identical Masked ROM Version (Z8C520)
■ On-Chip Oscillator that accepts a Ceramic Resonator or
    External Clock
■ Hardware Support for PS/2, Serial, USB, and GeneralPurpose I/O (GPIO)
■ Power Reduction Modes:
    – STOP Mode (functionality shut down except SMR)
    – HALT Mode (XTAL still running-peripherals active)
■ USB SIE Compliant with USB Spec 1.0
■ 4.0 VDC to 6.0 VDC Operating Range @ 0°C to +70°C