Toshiba Satellite M20 Maintenance Manual page 23

1.2 System Unit Block Diagram
− CardBus/PC Card controller
Video controller
• North Bridge embedded
− LCD control
− External RGB output control
− NTSC/PAL output control
Video RAM
• Up to 64MB shared with main memory
Sound controller
The ICH4-M integrated audio controller supports multimedia. The sound system
contains the following:
• MIDI replay feature
• Stereo speakers
• Headphone jack
• External microphone jack
• ICH4-M integrated audio controller + AD1981B
− 3D sound (surround) feature
− 16-bit, 48-KHz stereo record/replay feature
− Full-duplex (simultaneous record/replay capability)
KBC/EC (Keyboard Controller/Embedded Controller)
A single LPC 47N253 chip is used to serve as KBC/ EC.and Super IO.
• KBC
− Scan controller function
− Interface controller function
− Controlling the switching between the AccuPoint and external PS/2
Satellite M20 Maintenance Manual
mouse or between the built-in keyboard and external PS/2 keyboard or
their simultaneous operation
1 Hardware Overview
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