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IDT CONFIDENTIAL
34
V 0.995 01/11
2009 INTEGRATED DEVICE TECHNOLOGY, INC.
92HD88
SINGLE CHIP PC AUDIO SYSTEM, CODEC+MONO SPEAKER AMPLIFIER+CAPLESS HP+LDO
2.23.1. General conditions in Aux Audio Mode:
HD Audio Link is off (RST# is 0, active, and BitClk is 0, inactive. CODEC does not need to mon-
itor BitClk to enter/exit this mode but must not depend on BitClk to operate.)
HD Audio CODEC analog and digital supplies are active.
Port A may be an optional headphone jack (Normal and Aux Audio Mode) or an internal micro-
phone port (Normal Mode only)
Port B connect to the system headphone jack.
Port C connects to the system microphone Jack
Port D connects to the internal speakers.
Port E is not present on the CODEC but the port presence detect is available and used to con-
trol internal resources.
Port F is connected to the dock AUX Audio In (it is an input port)
EAPD is used to control the power state of the mixer, BTL amplifier, and headphone amplifiers.
The amplifiers are off if EAPD is held low.
Internal circuitry will delay enabling (change power state, un-mute, etc.) the output amplifiers
after the application of power or EAPD=1 to prevent pops.
Internal circuitry will orchestrate power down (EAPD = 0) to prevent pops.
EAPD must be forced low before removing power.
No special Dock Present signal needed. Only port presence detect for port E is used to disable
the speaker amplifier if the docked device has something plugged into its headphone jack.
DCN HDA015-B “clock-less D3” operation presents a problem. Clock Stop OK or similar commu-
nication will be used to prevent problems when an OS driver attempts to put the HD Audio bus
controller into D3 to save power. The bus must not be place into reset with the clock stopped or
unless EAPD is forced low or D3cold has been set. The Enable bit in the Aux Audio vendor spe-
cific verb is provided so firmware or other software can disable Aux Audio support and allow
stopping the HD Audio bus when an OS is in an active state. The default value of this bit is deter-
mined by a bond option and may be determined by reading the device ID. This bit only returns to
its default value when a power on reset event is generated.
2.23.2. “Playback Path” Port Behavior
Port F (Aux Audio In) input is routed to Port D (“internal speakers”) and Ports A&B (system head-
phone jacks) through the analog mixer.
2.23.3. When Port E presence detect = 0
Presence detect for Port E = 0 (nothing plugged in)
Port F, the “Aux Audio In”, input is routed to Port A, B, or D when that port is active.
If either Port A or Port B is in use (port presence detect = 1), Port D, internal speakers, will be
inactive (off)
To save power, the power supply for Port B will be active only if Port B is in use (Port B presence
detect = 1).
If neither Port A nor Port B is in use (port presence detect = 0), Port D, internal speakers, will be
active and ports A and B will be inactive.
EAPD must not be forced low due to the dock being absent or high when a dock is present.
EAPD is used to indicate if AUX Audio Mode is in use.