TLC320AD91 Datasheet, PDF (22/43 Pages) Texas Instruments – Stereo Audio Codec

2.3.1 Reset Register (Index 00h)
A write of any value to the Reset register performs a register reset, which causes all of the registers to revert
to their default values. A read of this register returns the ID code of the TLC320AD91C and the type of 3D
enhancement, if installed.
Both DACs operate at 18-bit resolution, and both ADCs operate at 18-bit resolution.
The ID decodes the capabilities of the TLC320AD91C based on the definitions listed in Table 2–5.
Table 2–5. Reset Register ID Bit Definitions
ALL BITS = 0
ID0
ID1
ID2
ID3
ID4
ID5
ID6
ID7
ID8
ID9
FUNCTION
Dedicated mic PCM channel
Modem line codec support
Bass and treble control
Simulated stereo (mono to stereo)
Headphone out support
Loudness (bass boost) support
18-bit DAC resolution
20-bit DAC resolution
18-bit ADC resolution
20-bit ADC resolution
2.3.2 Play Master Volume Stereo and Mono Registers (Index 02h and 06h)
The Play Master Volume registers manage output signal volumes. Register 02h controls the stereo master
volume (both right and left channels). Register 06h controls the mono volume output. Each step corresponds
to 1.5 dB. ML5 through ML0 is for the left channel level. MR5 through MR0 is for the right channel level. MM5
through MM0 is for the mono out channel.
The MSB is the mute bit and is supported in the TLC320AD91C. When this bit is set to 1, the level for that
channel is set at maximum attenuation.
The default value of these registers is 8000h (1000 0000 0000 0000) which corresponds to 0-dB attenuation
with mute on. The Play Master Volume register definitions are listed in Table 2–6.
Table 2–6. Play Master Volume Register Definitions
MUTE
0
1
Mx5 – Mx0
00 0000
...
01 1111
xx xxxx
FUNCTION
0-dB Attenuation
...
46.5-dB Attenuation
Maximum attenuation (mute)
2.3.3 PCBEEP Volume Register (Index 0Ah)
The PCBEEP Volume register controls the level of the PCBEEP input. Each step corresponds to 3 dB of
attenuation. The MSB of the register is the mute bit. When this bit is set to 1, the level for the channel is set
at maximum attenuation.
NOTE:
Power-on self-test (POST) codes need to be heard by the user when a hardware
problem with the PC exists, even when the TLC320AD91C is in a reset state.
Therefore, PCBEEP is routed to the left and right line outputs (a high-impedance
path to the outputs is used with no attenuation).
2–10