Cirrus Logic CS4382A - Manual (Page 25)

DS618F2 25
CS4382A
In Software Mode, the required de-emphasis filter coefficients for 32 kHz, 44.1 kHz, or 48 kHz are selected
via the de-emphasis control bits.
In Hardware Mode, only the 44.1 kHz coefficient is available (enabled through the M2 pin). If the input sam-
ple rate is not 44.1 kHz and de-emphasis has been selected, the corner frequencies of the de-emphasis
filter will be scaled by a factor of the actual Fs over 44,100.
4.7 ATAPI Specification
The CS4382A implements the channel mixing functions of the ATAPI CD-ROM specification. The
ATAPI functions are applied per A-B pair. Refer to
Table 8 on page 41 and Figure 14 for additional informa-
tion.
Gain
dB
-10dB
0dB
Frequency
T2 = 15 µs
T1=50 µs
F1 F2
3.183 kHz 10.61 kHz
Figure 13. De-Emphasis Curve
Σ Σ
A Channel
Volume
Control
Aout Ax
AoutBx
Left Channel
Audio Data
Right Channel
Audio Data
B Channel
Volume
Control
MUTE
MUTE
SDINx
Figure 14. ATAPI Block Diagram (x = channel pair 1, 2, 3, or 4)