Theory of Operation 4-11
♦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