CS4299-BQ_06 Datasheet, PDF (11/52 Pages) Cirrus Logic – CrystalClear SoundFusion Audio Codec 97

C_CS_S4₄2₂9₉9₉-_-B_BQ_Q
tain the read data in its Slot 2. Write operations are
similar, with the register index in Slot 1 and the
write data in Slot 2 of a SDATA_OUT frame. The
function of each input and output frame is detailed
in Section 3, AC Link Frame Definition. Individual
register descriptions are found in Section 4, Regis-
ter Interface.
2.3 Sample Rate Converters
The Sample Rate Converters (SRCs) provide high
accuracy digital filters supporting sample frequen-
cies other than 48 kHz to be captured from the
CS4299 or played from the controller. AC ’97 re-
quires support for two audio rates (44.1 and
48kHz). In addition, the Intel^® I/O Controller Hub
(ICHx) specification requires support for five more
audio rates (8, 11.025, 16, 22.05, and 32). The
CS4299 supports all these rate, as shown in Table 7
on page 29.
2.4 Output Mixer
The CS4299-BQ has two output mixers, illustrated
in Figure 8. The stereo output mixer sums together
the analog inputs to the CS4299-BQ, including the
PC_BEEP and PHONE signals, according to the
settings in the volume control registers. The stereo
output mix is sent to the LINE_OUT and
ALT_LINE_OUT pins on the CS4299-BQ. The
mono output mixer generates a monophonic sum of
the left and right channels from the stereo input
mixer. The mono output mix is sent to the
MONO_OUT output pin on the CS4299-BQ.
2.5 Input Mux
The input multiplexer controls which analog input
is sent to the ADCs. The output of the input mux is
converted to stereo 18-bit digital PCM data and
sent to the controller by means of the AC-link
SDATA_IN signal.
2.6 Volume Control
The CS4299-BQ volume registers control analog
input levels to the input mixer and analog output
levels, including the master volume level, and the
alternate volume level. The PC_BEEP volume con-
trol uses 3 dB steps with a range of 0 dB to -45 dB
attenuation. All other analog volume controls use
1.5 dB steps. The analog inputs have a mixing
range of +12 dB signal gain to -34.5 dB signal at-
tenuation. The analog output volume controls have
from 0 dB to -94.5 dB attenuation for LINE_OUT
and from 0 dB to -46.5 dB attenuation for
ALT_LINE_OUT and MONO_OUT.
DS319-BQPP2
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