VT82C686B
I/O Offset 5-4 - Power Management Control .................RW
15 Soft Resume
I/O Offset 0B-08 - Power Management Timer............... RW
31-24 Extended Timer Value (ETM_VAL)
This field reads back 0 if the 24-bit timer option is
selected (Rx41 bit-3).
........................................ always reads 0
(SLP_EN)...................... always reads 0
14 Reserved
13 Sleep Enable
This is a write-only bit; reads from this bit always
return zero. Writing a one to this bit causes the
system to sequence into the sleep (suspend) state
defined by the SLP_TYP field.
23-0 Timer Value (TMR_VAL)
This read-only field returns the running count of the
power management timer. This is a 24/32-bit counter
that runs off a 3.579545 MHz clock, and counts while
in the S0 (working) system state. The timer is reset to
an initial value of zero during a reset, and then
continues counting until the 14.31818 MHz input to
the chip is stopped. If the clock is restarted without a
reset, then the counter will continue counting from
where it stopped.
(SLP_TYP)
12-10 Sleep Type
000 Normal On
001 Suspend to RAM (STR)
010 Suspend to Disk (STD) (also called Soft Off).
The VCC power plane is turned off while the
VCCS and VBAT planes remain on.
011 Reserved
100 Power On Suspend without Reset
101 Power On Suspend with CPU Reset
110 Power On Suspend with CPU/PCI Reset
111 Reserved
In any sleep state, there is minimal interface between
powered and non-powered planes so that the effort
for hardware design may be well managed.
........................................ always reads 0
STD Command Generates System Reset Only
9
8
Reserved
0
1
Disable ...................................................default
Enable
........................................ always reads 0
(GBL_RLS) ............ , default = 0
7-3 Reserved
2
Global Release
WO
This bit is set by ACPI software to indicate the
release of the SCI / SMI lock. Upon setting of this
bit, the hardware automatically sets the BIOS_STS
bit. The bit is cleared by hardware when the
BIOS_STS bit is cleared by software. Note that the
setting of this bit will cause an SMI to be generated if
the BIOS_EN bit is set (bit-5 of the Global Enable
register at offset 2Ah).
(BMS_RLD)
Bus Master Reload
1
0
0
Bus master requests are ignored by power
management logic...................................default
Bus master requests transition the processor
from the C3 state to the C0 state
1
(SCI_EN)
SCI Enable
Selects the power management event to generate
either an SCI or SMI (for Power / Sleep Buttons &
RTC only)
0
1
Generate SMI .........................................default
Generate SCI
Note that certain power management events can be
programmed individually to generate an SCI or SMI
independent of the setting of this bit (refer to the
General Purpose SCI Enable and General Purpose
SMI Enable registers at offsets 22 and 24). Also,
TMR_STS & GBL_STS always generate SCI and
BIOS_STS always generates SMI.
Revision 1.71 June 9, 2000
-91-
Power Management I/O-Space Registers
ETC [ ETC ]
