
Publication Release Date: Jul., 2002
Revision 1.0
6
W83301DR-O
7. Functional Description
7.1 ACPI State Control
In order to meet the ACPI specification, the W83301DR-O implements an internal state
machine to generate ACPI-compliant power state transition.
There are five states in the state machine, the five states are G3 (Mechanical-Off State),
S0 (Full-Power State), S3 (Sleeping State-Suspend to RAM), S5
On
(Soft-Off State), S5
Off
and all of the state changes to the other according to the value of S3#, S5# and 5V
DLEN
#.
On the other hand, cause of the W83301DR-O allows the user to disable/enable the 5V
DUAL
output in S5 state via the 5V
DLEN
# pin, there are two states - S5
On
and S5
Off
, corresponding
to S5 state. Besides, a soft ramp-up mechanism is needed to protect the 5V
DL
output from
the rush current attack during the S5
Off
to S5
On
state
transition. Same as the 5V
DL
output,
the W83301DR-O also implements soft ramp-up mechanism in each STR outputs during
the S5
On
state transfers to the S0 state.
As the internal state machine, when the power turns on, the voltage of 5VSB of the ATX
power supply ramps up to 4.5V, the chip will enters the S5
Off
state from the G3 state, and
will enters the S5
On
state if the signal of 5V
DLEN
#=0 and S5#=0; When the signals S3#=1
and S5#=1, the system will enters the S0 state from S5
off
.
In the S5
On
state, the chip will returns back to the S5
Off
state if the 5V
DLEN
#=1 is set.
When the system in the S0 state, the system will enters the S3 (S3#=0, S5#=1) or S5
(S5#=0) state when the system is idle for a long time or user presses the power button.
When the system enters the S3 state, the system will waked up and enter the S0 state
by (S3#=1, S5#=1,PWOK=1), or gets into S5 state by (S5#=0).
Table 1.
W83301DR-O Outputs Table
State
G3
5V
DL
Off
Off
3V
DL
Off
On
STR1
Off
Off
STR2
Off
Off
LUV Activity *
No
No
S5 (5V
DL
Off)
(Driven by 3V
DLSB
)
On
(Driven by 3V
DLSB
)
On
(Driven by 3V
DRV
)
On
(Driven by 3V
DLSB
)
S5 (5V
DL
On)
On
(Driven by 5V
DLSB
)
On
(Driven by 5V
DRV
)
On
(Driven by 5V
DLSB
)
Off
Off
No
S0
On
On
Yes
S3
On
On
Yes
* Only the STR1 has linear under voltage function.