Cirrus Logic CS48LV13 - Manual (Page 7)

7 DS1057F1
3.1 Cirrus Logic 32-bit DSP Core
Figure 3-2. CS48LV13 Block Diagram
3.1 Cirrus Logic 32-bit DSP Core
The core is a high-performance, 32-bit, fixed-point DSP that is capable of performing two multiply-and-accumulate (MAC)
operations per clock cycle. The core has eight 72-bit accumulators, four X- and four Y-data registers, and 12 index
registers. It can operate up to 130 MHz, depending on mode and concurrency requirements, but it may also operate at low
speed to support specialized low-power modes, such as always-on voice wake.
The DSP core is coupled to a flexible DMA engine. The DMA engine can move data between peripherals such as the
multi-channel serial audio port, or any DSP core memory, without the intervention of the DSP. The DMA engine off-loads
data move instructions from the DSP core, leaving more MIPS available for signal-processing instructions.
3.2 Processing Groups
Providing consistent high-quality Tx and Rx voice streams in constantly changing environments requires a complex data
flow with constant interaction between various functional modules. While the actual data flow is more complex and not
linear, the architecture can be approximated as a set of in-line processing groups or chains that operate in different modes
depending on the current use model as follows.
CS48LV12:
1. Tx Voice DSP Chain
2. Rx Voice DSP Chain
3. Voice DSP Control and Detection
4. Audio Playback DSP Chain
Co
d
ec
Ho
st
PGA
Noise
Reduction
Acoustic Echo Canceller
Residual Echo Suppressor
NLP
Spectrally Matched
Comfort Noise
Dynamic
FlexEQ
ALC
PGA
C
od
ec P
or
t
Ho
st
P
o
rt
Full-Duplex Control + Voice Activity Detection + Double-Talk Detection
PGA
Comfort
Noise
Automatic Volume
Control
Automatic Level
Control
Dynamic
FlexEQ
Noise
Reduction
PGA
GND V
D
V
L
BUSY PLL/ClkMgr
I 2 S
Raw
PCM
I 2 S
Clean
PCM
I 2 S
Clean
PCM
I 2 S
Raw
PCM
Near
End
Far
End
Advanced Media Processor
SoundClear ASR Enhance™
SPI/I 2 C
RESET
Optional Voice Processing Features
Optional Postprocessing Features
Voice Activity
Detector
SoundClear
ASR Enhance™
Sensory Inc.
TrulyHandsfree™ Voice Control
Dolby Laboratories, Inc. Audio Postprocessing Algorithms
DTS, Inc. Audio Postprocessing Algorithms