
IDT CONFIDENTIAL
31
V 0.987 11/09
2009 INTEGRATED DEVICE TECHNOLOGY, INC.
92HD81
SINGLE CHIP PC AUDIO SYSTEM, CODEC+SPEAKER AMPLIFIER+CAPLESS HP+LDO
BTL SD
MODE
BTL SD INV
EAPD Pin
State
Amp State
0
Amplifier is mute (default1)
1.EAPD bit is set to one by default but the EAPD state is 0 after power-on reset because the function group is not in
D0. The state after a single or double function group reset will be compliant with ECR15b.
0
1
Amplifier is active
0
1
0
Amplifier is active
0
1
Amplifier is mute
0
1
0
Amplifier is in a low power state
0
1
0
1
Amplifier is active
0
1
0
Amplifier is active
0
1
Amplifier is in a low power state
1
0
NA
Amplifier follows pin/function group power state and will mute
when disabled
1
NA
Amplifier follows pin/function group power state and will enter a
low power state when disabled
Table 8. BTL Amp Status
HP SD
MODE
HP SD INV
EAPD Pin
State
Headphone Amp State
0
Amplifier is mute (default1)
1.EAPD bit is set to one by default but the EAPD state is 0 after power-on reset because the function group
is not in D0. The state after a single or double function group reset will be compliant with ECR15b.
0
1
Amplifier is active
0
1
0
Amplifier is active
0
1
Amplifier is mute
0
1
0
Amplifier is in a low power state
0
1
0
1
Amplifier is active
0
1
0
Amplifier is active
0
1
Amplifier is in a low power state
1
0
NA
Amplifier follows pin/function group power state and will
mute when disabled
1
NA
Amplifier follows pin/function group power state and will
enter a low power state when disabled
Table 9. Headphone Amp Enable Configuration
BEEP
Override
EAPD Pin value1
1.
When pin is enabled as Open Drain or CMOS output.
Description
0
Forced to low when in D2
or D3
Follows description in HD Audio spec. External amplifier is shut down when pin or function
group power state is D2 or D3 independent of value in EAPD bit.
1
Always follows EAPD bit
Power state is ignored and EAPD pin follows EAPD bit value only to allow PC_Beep support
in D2 and D3
Table 10. EAPD Low Power Behavior