TLC320AD91 Datasheet, PDF (39/43 Pages) Texas Instruments – Stereo Audio Codec

5 Application Information/System Usage
The system diagram in Figure 5–1 shows the essential components, including the TLC320AD91C, used in
the design of a system. In this scenario, the TLC320AD91C operates at the fixed sample rate of 48 kHz
and performs digital-to-analog conversion, analog-to-digital conversion, analog input, mixing, and allows
for the insertion of analog and digital signal processing (3D sound, stereo enhancement, etc).
PCI
BUS
Digital Controller
Sample Rate Conversion
Sound Blaster Registers
Synthesis
AC-3
DirectX
etc.
AC-Link
AD91 Codec
Analog I/O
ADC
DAC
Analog Mixer
Digital Interface
Analog Output
Game Port
Volume Up/Down
Mute
Analog Inputs
Figure 5–1. System Diagram
The digital controller, generally connected to the PCI bus, performs the following functions:
• Sample rate conversion to and from 48 kHz
• Sound Blaster compatibility
• FM synthesis
• Wave table synthesis
• Direct Sound acceleration (optional)
• AC-3 decode
The digital link is an AC‘97 compatible bidirectional, 5-wire, serial TDM format interface designed for a
dedicated point-to-point interconnect on a circuit board.
5.1 Software Driver Support for the Texas Instruments TLC320AD91C Stereo
Codec
The TLC320AD91C codec is compatible with software drivers developed to conform to the AC‘97 audio
codec specification.
With the use of an AC‘97 compliant digital controller, the TLC320AD91C can perform high quality (90-dB
SNR) sample rate conversions on a minimum of four simultaneous channels (stereo in and stereo out) and
between a variety of sample rates. With the input sample rate at 48 kHz, data conversion to 8, 11.025, 16,
22.05, 32, and 44.1 kHz are possible.
Mono PCM always translates to two mono channels ( L and R) on the AC‘97 AC-Link.
5–1