92hd89d Integrated Device Technology, 92hd89d Datasheet - Page 32

• Manufacturer Part Number: 92hd89d
• Description: Eight Channel Hd Audio Codec Low Power Optimized For Ecr15b And Eup
• Manufacturer: Integrated Device Technology

92HD89D
Eight channel HD Audio codec optimized for low power
©2009 INTEGRATED DEVICE TECHNOLOGY, INC.
2.16. Digital PC-Beep
2.17. Headphone Drivers
Bit_Clk
Reset#
This block uses an 8-bit divider value to generate the PC beep from the 48kHz HD Audio Sync
pulse. The digital PC_Beep block generates the beep tone on all Pin Complexes that are currently
configured as outputs. The HD Audio spec states that the beep tone frequency = (48kHz HD Audio
SYNC rate) / (4*Divider), producing tones from 47 Hz to 12 kHz (logarithmic scale). Other audio
sources are disabled when digital PC_Beep is active.
It should be noted that digital PC Beep is disabled if the divider = 00h.
PC-Beep may be attenuated and distorted when the CODEC is in D3 depending on the load imped-
ance seen by the output amplifier since all ports are in a low power state while in D3. Load imped-
ances of 10K or larger can support full scale outputs but lower impedance loads will distort unless
the output amplitude is reduced. Digital PC_Beep requires a clock to operate and the CODEC will
prevent the system from stopping the bus clock while in D3 by setting the Clock_Stop_OK bit to 0 to
indicate that the part requires a clock.
The codec implements headphone capable outputs on some ports. The Microsoft Windows Logo
Program allows up to the equivalent of 100ohms in series. However, an output level of +3dBV at the
pin is required to support 300mV at the jack with a 32ohm load and 1V with a 320 ohm load. Micro-
soft allows device and system manufactures to limit output voltages to address EU safety require-
ments. (WLP 3.09 - please refer to the latest Windows Logo Program requirements from Microsoft.)
Power limiting may be implemented through the use of an external series resistance.
Although 3 Headphone amplifiers are present, only two may be used simultaneously. Headphone
performance will degrade if more than one port is driving a 32 ohm load.
Beep enabled by
Driver
Analog PC_Beep Behavior – D3 clockless
Bus Driver sets
controller to D3
due to inactivity
Vista or Linux
32
Beep Enabled
Bus Driver sets
controller to D0
V1.0 04/10
92HD89D