HP KAYAK XU800 Management, Enhanced Power, Real Time Clock, Timer/Counter Block

2 System Board

The Input/Output Controller Hub (82801AA)

Timer/Counter Block The timer/counter block contains three counters that are equivalent in function to those found in one 82C54 programmable interval counter/timer. These three counters are combined to provide the system timer function, and speaker tone. The 14.318 MHz oscillator input provides the clock source for these three counters.

Advanced Programmable Interrupt Controller

Real Time ClockEnhanced PowerManagement

Incorporated in the ICH, the APIC can be used in either single-processor or multi-processor systems, while the standard interrupt controller supports only single-processor systems.

The RTC is 146818A-compatible, with 256 bytes of CMOS. The RTC performs two key functions: keeping track of the time of day and storing system data.

The RTC operates on a 32.768 kHz crystal and a separate 3V lithium battery that provides up to 7 years of protection for an unplugged system. It also supports two lockable memory ranges. By setting bits in the configuration space, two 8-byte ranges can be locked to read and write accesses. This prevents unauthorized reading of passwords or other security information. Another feature is a date alarm allowing for a schedule wake-up event up to 30 days in advance.

The ICH’s power management functions include enhanced clock control, local and global monitoring support for 14 individual devices, and various low-power (suspend) states. A hardware-based thermal management circuit permits software-independent entry points for low-power states.

The ICH includes full support for the Advanced Configuration and Power Interface (ACPI) specifications.

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