Cirrus Logic CS4244 - Manual (Page 37)

DS900F1 37
CS4244
4.6.3 DAC1-4 Path
The AOUT1-4 signals are driven by the data placed into the DAC1-4 path. This data can be placed into
the DAC1-4 path via the
DAC1-4 Data Source settings in the control port. These settings allow the input
source to be selected from any of the up to 32 slots of data on the incoming TDM streams on SDIN1 and
SDIN2.
The DAC1-4 path also includes individual channel mutes. Separate volume controls are available for each
channel, along with a master volume control that simultaneously attenuates all four channels. The master
volume attenuation is added to any channel attenuation that is applied.
4.6.3.1 De-emphasis Filter
The CS4244 includes on-chip digital de-emphasis for 32, 44.1, and 48 kHz sample rates. It is not support-
ed for 96 kHz or for any settings in Double-speed Mode. The filter response is adjusted to be appropriate
for a particular base rate by the
Base Rate Advisory bits. This filter response, shown in Figure 27 , will vary
if these bits are not set appropriately for the given base rate. The frequency response of the de-emphasis
curve scales proportionally with changes in sample rate, F
S
. Please see Section 6.9.2 DAC1-4 De-em-
phasis for de-emphasis control.
The de-emphasis feature is included to accommodate audio recordings that utilize 50/15 s pre-emphasis
equalization as a means of noise reduction.
I 2 C Control
Data
Control Port
Level Translator
VL
1.8 to 5.0 VDC
RST INT SDOUT1
LDO Analog Supply 2.5 V
VA
5.0 VDC
VD
2.5 VDC
Serial Audio Interface
SDOUT2 Serial Clock
In/Out
Master Clock In Frame Sync
Clock / LRCK
SDIN1 SDIN2
AOUT1 (±)
AOUT2 (±)
AOUT3 (±)
AOUT4 (±)
Interpolation
Filter
Multi-bit 
Modulators
Channel Volume ,
Mute, Invert,
Noise Gate
DAC &
Analog
Filters
Master
Volume
Control
AIN4 (±)
AIN3 (±)
AIN2 (±)
AIN1 (±)
Digital Filters
Multi-bit
 ADC
Figure 26. DAC1-4 Path