Device Overview
The MC9S08SG8 members of the low-cost, high-performance HCS08 Family of 8-bit microcontroller units (MCUs). All MCUs in the family use the enhanced HCS08 core and are available with a variety of modules, memory sizes, memory types, and package types.

MC9S08SG8 Features
8-Bit HCS08 Central Processor Unit (CPU)
• 40-MHz HCS08 CPU (central processor unit)
• HC08 instruction set with added BGND instruction
• Support for up to 32 interrupt/reset sources
On-Chip Memory
• FLASH read/program/erase over full operating voltage and temperature
• Random-access memory (RAM)
Power-Saving Modes
• Two very low power stop modes
• Reduced power wait mode
• Very low power real time interrupt for use in run, wait, and stop
Clock Source Options
• Oscillator (XOSC) — Loop-control Pierce oscillator; Crystal or ceramic resonator range of 31.25 kHz to 38.4 kHz or 1 MHz to 16MHz
• Internal Clock Source (ICS) — Internal clock source module containing a frequency-locked loop (FLL) controlled by internal or external reference; precision trimming of internal reference allows 0.2% resolution and 2% deviation over temperature and voltage; supports bus frequencies from 2MHz to 20MHz.
System Protection
• Watchdog computer operating properly (COP) reset with option to run from dedicated 1-kHz internal clock source or bus clock
• Low-voltage detection with reset or interrupt; selectable trip points
• Illegal opcode detection with reset
• Illegal address detection with reset
• FLASH block protect
Development Support
• Single-wire background debug interface
• Breakpoint capability to allow single breakpoint setting during in-circuit debugging (plus two more breakpoints in on-chip debug module)
• On-chip, in-circuit emulation (ICE) debug module containing two comparators and nine trigger modes. Eight deep FIFO for storing change-of-flow address and event-only data. Debug module supports both tag and force
breakpoints.