GENERAL DESCRIPTION
OVERVIEW
The System Energy Manager is a highly integrated microcontroller that provides several key features for systems including key scanning and control, battery and power management, as well as two 2–Wire serial I/O Ports. It incorporates the Dallas 8051–compatible high–speed microcontroller core which has been redesigned to eliminate wasted clock and memory cycles. Every standard 8051 instruction is executed between 1.5 and 3 times faster than the original for the same crystal speed.

DETAILED FEATURE SUMMARY
• High Speed 80C32 Compatible Core:
    – High performance 4 clocks / machine cycle (8032 = 12)
    – Low Power: typically 1/3 power for equivalent 8032 throughput
    – Maximum clock speed up to 25 MHz at 5.0V
    – Ultra–low stop mode power (typ. 1 uA) and “IDLE” mode (typ. 10 mA)
    – Multiple wake–up sources from STOP including key scan, 2–wire, host I/F, or external interrupt
    – Three 16–bit timers, 1 serial port
    – 256 byte scratchpad
    – 256 bytes MOVX RAM
• Keyboard Control:
    – Replaces 8042 and key scan microcontroller
    – 2 Parallel I/O ports for key scan outputs
    – One interrupt–driven 8–bit input port to initiate key–scan sequence
• Input/Output:
    – Total of eleven 8–bit I/O ports; all pins can be individually programmed to serve as general purpose digital input/output.
    – Each 8–bit port supports one or more special functions:
        Port 0, 2, 3: External program / data memory interface
        Port 1, 3: UART, 2–Wire serial, timers, and external interrupt I/O.
        Port 4, 8, 9: Key scan input / output
        Port 5: A/D inputs
        Port 6: PWM Outputs
        Port 7: Activity monitor, LED Control
        Port 10: GPIO
• Analog Input/Output:
    – Eight–channel, 10–bit A/D with power down mode supports charging NiMH rechargeable cells
    – 4–channel, 8–bit PWM supports LCD brightness and contrast control
• 2–Wire Bi–directional Serial Buses
    – Master/slave multi–drop operation
    – Manages on–board slaves or external I/O devices
• Power Control
    – Generates system power on reset
    – Programmable power down pin states