w83977f Winbond Electronics Corp America, w83977f Datasheet - Page 112

• Manufacturer Part Number: w83977f
• Description: Plug & Play 1.0a Compliant
• Manufacturer: Winbond Electronics Corp America

6.4 "On-Now" Control
The "On-Now" Control function is built in RTC. It enables the PC to be powered on automatically
from triggers of various events, and to be powered off in an orderly controlled fashion.
The "On-Now" works at all times even when the system power is switch-off or disconnected. It
detects several external events to control system power supply On/Off properly (e.g. telephone ring,
panel switch-off). It also controls the signal (PSCTRL ) to turn the power supply on or off.
6.5 Power-On Events
The "On-Now" Control turns on power supply when one of the following events occurs:
(Note: Panel-Switch has a debounce circuit which is clocked by RTC 32.768KHz oscillator. The "On-Now" control will not function
properly if this oscillator fails to work and PC can not be powered-on consequently)
6.6 Power-Off Events
to turn off immediately
Panel Switch "turned on"
Telephone is ringing
Ring-In detection signal comes from a modem
Keyboard/Mouse is stroked/moved
Power-wake-up input goes from high to low.
Panel Switch "turned off"
Power-off under software control
Power-failure event
Override Power off: Panel switch is pushed for at least 4 seconds, then the system will be forced
PSCTRL active when power returns after a power-failure occurs.
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W83977F/ W83977AF
Publication Release Date: January 1997
PRELIMINARY
Revision 0.50