
SiS5595 PCI System I/O Chipset
Preliminary V2.0 Nov. 2, 1998 48 Silicon Integrated Systems Corporation
Hot Key Match Event and Password Match Event :
SiS5595 build-in Keyboard Controller can generate two special events to power up the
system. They are Hot Key Match Event and Password Match Event. These two functions will
be disabled automatically while internal keyboard controller’s power is suddenly off. Please
refer to Keyboard Controller for more detail.
RTC Alarm On Event :
When the time value of RTC matches the corresponding alarm bytes, the RTC would send
an “RTC Alarm Event” to the APC module. RTC alarm event can be created form once per
second to once per year. Beside the standard RTC Alarm power up function, SiS5595 also
provides an additional power up function called the “Day of the Week Alarm Power Up”.
Following are the detail description of these two alarm power-up functions:
RTC Alarm Power Up Function :
f APC_EN and ALMUP_EN are enabled and the system is in power down state, an RTC
Alarm Event will power up the system.
Day of the Week Alarm Power Up Function:
The
Day of the Week Alarm Power Up
Function can be enabled to power up the system on
selected days within a week. With this additional feature, SiS5595 allows the user to power
up the system, say, at 08:00 on each working day, and to stay at power off state on
weekend. The Day of the Week Alarm Power Up byte is located in APC register 02h. Note
that this feature is enabled when APC_EN and DWAUP_EN bits are both enabled, and
ALMUP_EN is disabled.
Ring Up Event :
While PWRGD is low, the detection of an active RING pulse lasting for more than 4ms would
activate the PS_ON#. Note that the active high/low logic of the RING can be defined through
programming RN_POL. While PWRGD is high, the detection of RING pulse would generate
an SCI/SMI# event, which will be recognized and responded by ACPI. Please refer to ACPI
section for more details.
RING
RN_POL
APC03h[4]
4ms Debounce
RNUP Event
Figure 3.7-4 Ring Up Event
Power Manage Event 1 :
When the power is removed, a high to low transition on PME1# indicates a power
management event which will activate PS_ON#. When this function is used, APC 04h[3]
must be set to 1 to configure this pin in input mode. This power up function can be used to
accept PCI or AGP power management event (PME#) when system is in power down state.