Compaq EN Series Personal Computer User Manual


 
Technical Reference Guide
Compaq Deskpro EN Series of Personal Computers
Desktop and Minitower Form Factors
Third Edition - September 1998
8-23
Standby - The computer is in a low power state: video is off, some subsystems may be drawing
less power, and the microprocessor is halted except for servicing interrupts. Video graphics
controller is under driver control and/or VSYNC is off and the power supply fan is turned off.
Any of the following activities will generate a wake-up SMI and return the system to On:
a. Keyboard
b. Mouse
c. Serial port
d. Diskette drive
e. Hard drive
f. RTC Alarm
If no APM connection is present, the BIOS will set an APM timer to 45 minutes, at which
time the Suspend will be entered if no activity has occurred. This function can be defeated (so
that Suspend will not be achieved). If an APM connection is present, the BIOS APM timer is
not used and Suspend is entered only by user request either through an icon in Windows 95 or
by pressing and releasing the power button under 4 seconds.
Suspend - The computer is in a low power state: video graphics controller is under driver control
and/or HSYNC and VSYNC are off, some subsystems may be drawing less power, and the
microprocessor is halted except for servicing interrupts. Any of the following activities will
generate a wake-up SMI and return the system to On:
a. Keyboard
b. Mouse
c. Serial port
d. Diskette drive
e. Hard drive
f. RTC Alarm
g. Network interface controller
The APM BIOS for this system supports APM 1.2 as well as previous versions 1.1 and 1.0. The
APM BIOS functions are listed in Table 8-3.
Table 8–2. APM BIOS Functions (INT15)
Table 8-3.
APM BIOS Functions (INT15)
AX Function
5300h APM Installation Check
5301h APM Connect (Real Mode)
5302h APM Connect (16-bit Protected Mode)
5303h APM Connect (32-bit Protected Mode)
5304h Interface Disconnect
5305h CPU Idle
5306h CPU Busy
5307h Set Power State [1]
5308h Enable/Disable Power Management
5309h Restore Power On Defaults
530Ah Get Power Status
530Bh Get PM Event
530Ch Get Power State
530Dh Enable/Disable Device Power Management
530Eh APM Driver Version
530Fh Engage/Disengage Power Management
5380h OEM (Compaq) Specific APM Function