92HD87 Datasheet, PDF (32/204 Pages) Integrated Device Technology – SINGLE CHIP PC AUDIO SYSTEM

92HD87
SINGLE CHIP PC AUDIO SYSTEM, CODEC+STEREO SPEAKER AMPLIFIER+CAPLESS HP+LDO
Docked – Headphones plugged into docked player
D-MIC
MIC
C
HP
A
HP
B
S
F
SPKR
D
Dock
Interface
Port E PD=1
Portable Media
Player
HP
BTL amp always off
Headphones on if plugged in
2.22.6. EAPD
Since the Aux Audio mode overrides the default behavior but not the actual port settings when in
reset, the logical state of the EAPD pin must be overridden as well. When Aux Audio mode is
enabled and the part is in reset as described above, the logical state of EAPD will be 1 (External
Amplifier Powered Up) unless held low by an external circuit. This ensures that audio pass-thru and
analog PC_Beep will be supported.
2.22.7. Analog PC_Beep
Analog PC_Beep may be supported in Aux Audio mode. By default, analog PC_Beep is disabled. If
the CODEC is programmed to enable analog PC_Beep and Aux Audio mode is enabled, the next
time reset is asserted, the analog PC_Beep pin will be mixed at each of the active outputs.
2.22.8. Firmware/Software Requirements:
The reconfiguration outlined in this chapter is enabled by default (without the help of firmware or OS
driver.)
This autonomous mode does not interfere with normal operation.
If it is desirable to stop the HD Audio bus while the CODEC is in D3 under OS control per DCN
HDA015-B, Firmware must disable the AUX Audio Mode support in the CODEC prior to loading the
OS. If Aux Audio Mode is not disabled in the CODEC, the CODEC will report to the OS driver that
stopping the bus clock while the CODEC is in D3 is not supported or not available.
IDT CONFIDENTIAL
32
©2009 INTEGRATED DEVICE TECHNOLOGY, INC.
V 0.995 01/11
92HD87