STAC9758 Datasheet, PDF (45/119 Pages) Integrated Device Technology – HIGH-PERFORMANCE 6-CHANNEL AC’97 2.3 CODEC WITH UNIVERSAL JACKS

STAC9758/9759
HIGH-PERFORMANCE 6-CHANNEL AC’97 2.3 CODEC WITH UNIVERSAL JACKS™
PC AUDIO
6. STAC9758/9759 MIXER
• Mixer Inputs
• Analog PC Beep, Digital PC Beep, Phone, Aux In, Line In (has pre-select mux for jack sharing/
Universal Jacks^TM), Mic In (mono and stereo modes - includes pre-select mux), DAC-A,
DAC-B
• Split-mute option on all stereo inputs allows left and right inputs to be muted independently.
• Analog Output Sources
• DAC-A, DAC-B, DAC-C, Stereo Mix, Mono
• Analog I/O
• Pins 21/22, 23/24, 35/36, 39/41, 43/44
• All Analog I/O pins have analog jack sense
• Pins 35/36 and 39/41 are capable of driving headphones
• All outputs are high impedance when powered down
• Split-mute (bit D7) option on all outputs allows left and right outputs to be muted independently.
6.1.
SPDIF Digital Mux
The STAC9758/9759 incorporates a digital output that supports SPDIF formats. A multiplexer deter-
mines which of two digital input streams are used for the digital output conversion process. These
two streams include the PCM OUT data from the audio controller and the ADC recorded output. The
normal analog LINE_OUT signal can be converted to the SPDIF formats by using the internal ADC
to record the MIX output, which is the combination of all analog and all digital sources. In the case of
digital controllers with support for 4 or more channels, the SPDIF output mode can be used to sup-
port compressed 6-channel output streams for delivery to home theater systems. These can be
routed on alternate AC-Link slots to the SPDIF output, while the standard 2-channel output is deliv-
ered as selected by bits D5 and D4 in Register 6Eh. If the digital controller supports 6 channels, a
SPDIF output with 4 analog channels can also be configured.
If the Digital Controller has independent DMA engines, SPDIF and Analog can be used simulta-
neously and independently.
6.2.
SPDIF_IN
The STAC9758 implements a multi-function pin in place of the traditional EAPD pin (pin 47). EAPD
functionality is supported as the default for compatibility with existing software. Advanced implemen-
tations can utilize this pin as an alternate GPIO or SPDIF_IN.
A sophisticated digital PLL allows automatic rate detection and accurate data recovery. The ability to
accept consumer SPDIF voltage levels directly eliminates the need for costly external receiver ICs.
Advanced features such as record slot select and SPDIF_IN routing to the surround DACs allows
simultaneous record and playback as well as multi-channel recording.
IDT™
45
HIGH-PERFORMANCE 6-CHANNEL AC’97 2.3 CODEC WITH UNIVERSAL JACKS™
STAC9758/9759
V 1.2 1206