Acer Extensa 900 Series Maintenance Manual page 67

Provides type F transfers
Interrupt controller
Provides 14 interrupt channels
Independently programmable level/edge triggered channels
Counter/Timers
Provides 8254 compatible timers for system timer, refresh request, speaker
output use
Keyboard controller
Built-in PS2/AT keyboard controller
The specific I/O is used to save the external TTL buffer
Real time clock
Built-in real time clock
128-byte CMOS RAM with 2
Plug-and-Play port support
Programmable chip select
Steerable interrupt request lines
PMU interface
Supports CPU SMM mode, SMI feature
Supports programmable stop clock throttle
Supports the APM control
Provides external suspend mode switch/turbo switch/ring-in switch
Provides four system states for power saving (on, doze, standby, suspend)
Provides three timers from 1 second to 300 minutes to individually monitor
VGA, MODE, IN status
Supports RTC alarm wake up control
IDE interface
Built-in PCI IDE master controller
Theory of Operation 4-11