INTEGRATED CIRCUITS
DATA SHEET
SAA2500
MPEG Audio Source Decoder
Preliminary specification
File under Integrated Circuits, IC01
September 1994
Philips Semiconductors
Philips Semiconductors
Preliminary specification
MPEG Audio Source Decoder
FEATURES
•
Advanced error protection
•
Integrated audio post processing for control of signal
level and inter-channel crosstalk
•
Demultiplexing of ancillary data in the input bitstream
•
Automatic digital de-emphasis of the decoded
audio signal
•
Separate master and slave inputs
•
Automatic sample frequency and bit-rate switching in
master input mode
•
Automatic synchronization of input and output interface
clocks in master input mode
•
Selectable audio output precision; 16, 18, 20 or 22 bit
•
Low power consumption.
ORDERING INFORMATION
PACKAGE
TYPE NUMBER
NAME
SAA2500H
Note
QFP44
(1)
DESCRIPTION
Plastic quad flat package; 44 leads (lead length 1.3 mm);
body 10
×
10
×
1.75 mm
APPLICATIONS
SAA2500
•
Cable and satellite digital radio decoders
•
Video CD
•
Compact Disc Interactive (CD-I)
•
Sold-state audio
•
Multimedia Personal Computer (PC).
GENERAL DESCRIPTION
The SAA2500 supports all audio modes (joint stereo,
stereo, single channel and dual channel) bit rates and
sample frequencies of ISO/MPEG-1 layers I and II, as
standardized in
“ISO/IEC 11172-3”.
VERSION
SOT307-2
1. When using IR reflow soldering it is recommended that the Drypack instructions in the
“Quality Reference
Pocketbook”
(order number 9398 510 34011) are followed.
Supply of this
“ISO/IEC 11172-3”
audio standard Layer I or layer II compatible IC does not convey a licence nor imply a
right under any patent, or any Industrial or Intellectual Property Right, to use this IC in any ready-to-use
electronic product.
September 1994
2
Philips Semiconductors
Preliminary specification
MPEG Audio Source Decoder
BLOCK DIAGRAM
SAA2500
FSCLK384
MCLKOUT
FSCLKIN
MCLK24
X22OUT
L3MODE
FSCLKM
MCLKIN
FSCLK
L3DATA
L3CLK
handbook, full pagewidth
5
TDI
TDO
TCK
TMS
TRST
CDS
CDSEF
CDSCL
CDSWA
CDSSY
CDM
CDMEF
CDMCL
CDMWS
41
37
39
40
38
19
20
18
21
22
15
14
16
13
34
8
7
4
44
10
9
3
2
42 43
24 25 23
11 12
URDA
1
X22IN
MCLK
V
DD1
V
DD2
CLOCK
GENERATOR
DECODING
CONTROL
STOP
RESET
SAA2500
DEQUANTI-
ZATION
AND
SCALING
PROCESSOR
SYNTHESYS
SUBBAND
FILTER
BANK
AND
OUTPUT
PROCESSING
INPUT
PROCESSOR
26
SD
36
TC0
35
TC1
17
GND
28
GND
6
GND
27 33 31 32
TA TB TO TI
29
30
MGB489
SCK WS
Fig.1 Functional block diagram.
September 1994
3
Philips Semiconductors
Preliminary specification
MPEG Audio Source Decoder
PINNING
SYMBOL
RESET
FSCLK
FSCLKIN
MCLK
V
DD1
GND
MCLKOUT
MCLKIN
X22OUT
X22IN
STOP
URDA
CDMWS
CDMEF
CDM
CDMCL
GND
CDSCL
CDS
CDSEF
CDSWA
CDSSY
L3CLK
L3DATA
L3MODE
SD
TA
GND
SCK
WS
TO
TI
TB
V
DD2
TC1
TC0
TDO
TRST
TCK
September 1994
PIN
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
master reset
sample rate clock; buffered signal
sample rate clock input
master clock; buffered signal
supply voltage
supply ground
master clock oscillator output
master clock oscillator input or signal input
22.579 MHz clock oscillator output
22.579 MHz clock oscillator input or signal input
stop decoding
unreliable data input; interrupt decoding
coded data (master input) word select output
coded data (master input) error flag input
ISO/MPEG coded data (master input)
coded data (master input) bit clock output
supply ground
coded data (slave input) bit clock
ISO/MPEG coded data (slave input)
coded data (slave input) error flag
coded data (slave input) window signal
coded data (slave input) frame sync
L3 interface bit clock
L3 interface serial data
L3 interface address/data select input
baseband audio I
2
S data output
do not connect; reserved
supply ground
baseband audio data I
2
S clock output
baseband audio data I
2
S word select output
connect to TI (pin 32)
connect to TO (pin 31)
do not connect; reserved
supply voltage
DESCRIPTION
SAA2500
TYPE
I
O
I
O
−
−
O
I
O
I
I
I
O
I
I
O
−
I
I
I
I
I
I
I/O
I
O
O
−
O
O
O
I
O
−
I
I
O
I
I
do not connect; factory test control 1 input, with integrated pull-down resistor
do not connect; factory test control 0 input, with integrated pull-down resistor
boundary scan test data output
boundary scan test reset input; this pin should be connected to ground for
normal operation
boundary scan test clock input
4
Philips Semiconductors
Preliminary specification
MPEG Audio Source Decoder
SAA2500
SYMBOL
TMS
TDI
FSCLK384
FSCLKM
MCLK24
PIN
40
41
42
43
44
boundary scan test data input
DESCRIPTION
boundary scan test mode select input
sample rate clock frequency indication input
sample rate clock source selection for the master input
master clock frequency indication
TYPE
I
I
I
I
I
43 FSCLKM
44 MCLK24
handbook, full pagewidth
handbook, full pagewidth
FSCLK384
38 TRST
40 TMS
37 TDO
39 TCK
36 TC0
41 TDI
35
42
34
V DD
TC1
RESET
FSCLK
FSCLKIN
MCLK
V DD
GND
MCLKOUT
MCLKIN
X22OUT
X22IN
STOP
1
2
3
4
5
6
7
8
9
10
11
33 TB
32 TI
31 TO
30 WS
29 SCK
SAA2500
(QFP44)
28 GND
27 TA
26 SD
25 L3MODE
24 L3DATA
23 L3CLK
URDA 12
CDMWS 13
CDMEF 14
CDM 15
CDMCL 16
GND 17
CDSCL 18
CDS 19
CDSEF 20
21
CDSSY 22
MGB490
Fig.2 Pin configuration.
FUNCTIONAL DESCRIPTION
Coding system
The perceptual audio encoding/decoding scheme defined
within the “ISO/IEC
11172-3 MPEG Standard”
allows for a
high reduction in the amount of data needed for digital
audio whilst maintaining a high perceived sound quality.
The coding is based upon a psycho-acoustic model of the
human auditory system. The coding scheme exploits the
fact that the human ear does not perceive weak spectral
components that are in the proximity (both in time and
frequency) of loud components. This phenomenon is
called masking.
September 1994
5
For layers I and II of ISO/MPEG the broadband audio
signal spectrum is split into 32 sub-bands of equal
bandwidth. For each sub-band signal a masking threshold
is calculated. The sub-band samples are then
re-quantized to such an accuracy that the spectral
distribution of the re-quantization noise does not exceed
the masking threshold. It is this reduction of representation
accuracy which yields the data reduction. The
re-quantized sub-band signals are multiplexed, together
with ancillary information regarding the actual
re-quantization, into a MPEG audio bitstream.
CDSWA
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
