Advanced Configuration and Power Interface Specification

Power Source and Power Meter Devices
Notify(battery_device, 0x82) if evaluating _BMC did not result in causing the Status Flags to be set
as indicated in that argument to _BMC. AML is not required to issue Notify(battery_device, 0x82) if
the Status Flags change while evaluating _BMC unless the change does not correspond to the
argument passed to _BMC.
Arguments:
None
Return Value:
A Package containing the battery maintenance data as described below
Return Value Information:
_BMD returns a package in the format below:
Package {
Status Flags
Capability Flags
Recalibrate Count
Quick Recalibrate Time
Slow Recalibrate Time
}
// Integer (DWORD)
// Integer (DWORD)
// Integer (DWORD)
// Integer (DWORD)
// Integer (DWORD)
Table 10-277 BMD Return Package Values
Field Format Description
Status
Flags
Capability
Flags
Integer
(DWORD)
Integer
(DWORD)
Bit values. Bit [0] is mutually exclusive with bit [1] and bit [2]. If the charger is
being manually controlled, there cannot be an AML controlled calibration cycle.
• Bit [0 ]– 1 indicates the battery is running an AML controlled calibration cycle
• Bit [1] – 1 indicates that charging has been disabled.
• Bit [2] – 1 indicates the battery is configured to discharge while AC power is
available.
• Bit [3] – 1 indicates that the battery should be recalibrated.
• Bit [4 ]– 1 indicates that the OS should put the system into standby to speed
charging during a calibration cycle. This is optional (based on user
preference) if “Slow Recalibrate Time” is not equal to 0x00000000.
• Bit [31:5] – reserved.
Bit values that describe the capabilities of the battery system. These bits allows
a battery system with more limited capabilities to still be calibrated by OSPM.
• Bit [0] – 1 indicates that an AML controlled calibration cycle is supported.
• Bit [1] – 1 indicates that disabling the charger is supported.
• Bit [2 ]– 1 indicates that discharging while running on AC is supported.
• Bit [3 ]– 1 indicates that calling _BMC for one battery will affect the state of all
batteries in the system. This is for battery systems that cannot control
batteries individually.
• Bit [4 ]– 1 indicates that calibration should be done by first fully charging the
battery and then discharging it. Not setting this bit will indicate that calibration
can be done by simply discharging the battery.
• Bit [31:5] – reserved.
Version 6.0 581