ETC CXD3027 Cd audio digital signal-processing lsi device with on-chip digital servo system allows listening without sound skipping Datasheet

CD Audio Digital Signal-Processing LSI Device
with On-Chip Digital Servo System
Allows Listening without Sound Skipping
CXD3027R-1
Sound skipping can be truly irritating when trying to enjoy music on a CD outdoors. People like to listen to their music without interruption, even when moving around.
Sony has now applied the firm’s high-level design technology
to resolving this problem. The result is an “ultra single chip”
product that adds a memory controller function (with data compression and expansion) for even better anti-shock performance
to Sony’s most powerful and functional CD digital signal-processing LSI device.
■
Memory controller functions, digital
signal processing, digital servo, DF,
D/A converter, and low-pass filter
circuits integrated on a single chip
■
Supports variable-speed playback
from 0.5 to 4× using CAV playback
mode.
■
Completely adjustment-free due to the
use of a digital servo system
■
Built-in DDBB*1 function
*1
DDBB: Digital Dynamic Bass Boost
While it goes without saying that this product will contribute to
the implementation of portable CD players for active users, this
device can also be used in CD players for car stereo systems.
High-Functionality Memory
Controller Function
CD players read out the digital signal
from the disc using a built-in pickup and
provide high-fidelity sound. However,
portable CD players often become unable to play back audio normally when,
for example, the user goes up or down
stairs and the mechanical shock applied
to the CD player causes the pickup to
lose focus, or the user simply walks normally and the swaying causes variations
in the rotation speed of the disc. In these
V
O
I
C
E
This LSI device can contribute to
improved anti-shock performance
by adding compression and expansion functions to a conventional
anti-shock memory controller. However, what was most memorable
for us was the fact that the psychological strength of the individual
members of the team grew as much
as did the resistance to mechanical
shock provided by this LSI device
while we were under the pressures
of the design process. I expect that
this device will be used in many
portable products, and I strongly
recommend that you consider it for
your designs, too.
cases, when the signal is interrupted, the
audio data is interrupted and a sound
skipping occurs. The CD player
memory controller function is a system
that saves audio information in an external memory (DRAM) in expectation
of a sound skipping occurring. This
function prevents sound skipping by
replacing the audio data from the disc
with the stored audio when the disc data
is interrupted by a mechanical shock. The
CXD3027R-1 supports DRAM capacities of 4M or 16M bits, and supports
compression/expansion for handling the
stored audio data. Applications can
choose one of four modes in which data
is stored in its original 16-bit word
length, compressed to 4 bits, compressed to 6 bits, or compressed to 8 bits.
If memory has been filled with data, the
CXD3027R-1 can continue providing
audio playback to the user for the fixed
periods (logical values) listed in table
1.
Digital Signal Processing
The CXD3027R-1 supports variable
playback speeds from 0.5 to 4×. This
system provides the following advantages since the anti-shock functions are
implemented for CAV playback.
• Since rough servo control of the motor speed can be used with the spindle
motor, the number of acceleration and
deceleration operations is reduced.
This reduces vibration and power
consumption.
• Since there is no need to change the
disc speed when jumping tracks, the
signal can be read out immediately.
This can reduce the access time.
Furthermore, since it was necessary to
integrate this memory controller
function on the same chip as the highfunctionality CD digital signal-processing LSI device, we fabricated the
CXD3027R-1 in a new process technology. This allowed power consumption
to be reduced.
On-Chip DDBB
The CXD3027R-1 provides a bass boost
function that requires no external components by using built-in digital filters.
Note that the amount of boost can be
varied according to the input level, i.e.
to function dynamically.
DSP
CXD3027R-1
DSP block
Optical
mechanism
KSM-780AAA
RF amp.
CXA1821M
Digital
PLL
CIRC
Digital servo
block
Driver IC
CXA2534Q
Memory
controller
for antishock
ECC
Output
Digital
filter
DAC
RAM
System
controller
SPC700
series
Servo DSP
4M-bit/
16M-bit
DRAM
Servo block
CPU
interface
MIRR
DFCT
FOK
Signal-processing
block
4M-bit
DRAM
16M-bit
DRAM
EFM
demodulator
LPF
LPF
Approx. 3 s
Approx. 11 s
Approx. 7 s
Approx. 5 s
Approx. 12 s
Approx. 44 s
Approx. 30 s
Approx. 22 s
DOUT
XRDE
XWRE
XOE
XCAS
XWE
XRAS
XQOK
XWIH
XEMP
D0 to D4
A0 to A11
SYSM
PCMDI
BCKI
LRCKI
LRMU
Digital
out
Time (logical value)
XTAI
XTAO
XTSL
VPCO
VCTL
XUGF
GFS
EMPH
WFCK
Error
corrector
Anti-shock memory controller
+
Compression/
expansion circuit
DAC
■ Table 1 Continuous Playback Times Provided during Mechanical Shock
Compression technique
No compression
4-bit compression
6-bit compression
8-bit compression
No compression
4-bit compression
6-bit compression
8-bit compression
Asymmetry
corrector
D/A
interface
Memory controller
Bass boost block
FOK
DFCT
MIRR
ATSK
SSTP
COUT
SCLK
FRDR
FFDR
TRDR
TFDR
SRDR
SFDR
Sub code
processor
■ Figure 2 CXD3027R-1 Block Diagram
DRAM
Digital
PLL
32K-bit
RAM
Servo
interface
LOUT2
AIN2
AOUT2
LOUT1
AIN1
AOUT1
Sled servo
Tracking servo
Servo DSP
Servo
auto
sequencer
PWM generator
Focus PWM
generator
Tracking PWM
generator
Sled PWM
generator
Focus servo
A/D
converter
Digital
CLV
Selector
PCMD
BCK
LRCK
XRST
TEST
TES1
OP amp.
analog SW
Clock
generator
BIAS
ASYO
ASYI
RFAC
IGEN
VC
FE
SE
TE
CE
RFDC
SOCK
SQSO
SCSY
EXCK
SBSO
SCOR
CLOK
XLAT
DATA
SENS
XSOE
PWMI
LOCK
MDP
CLTV
PCO
FILI
FILO
XPCK
■ Figure 1 CXD3027R-1 System Block Diagram
WDCK
C2PO
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