Siemens PEB2445-N Datasheet
ICs for Communications
Multipoint Switching and Conferencing Unit - Attenuation
MUSAC-A
PEB 2445 Version 1.2
Data Sheet 02.96
PEB 2445
Revision History: Current Version: 02.96
Previous Version: Digital Switching and Conferencing IC’s Data Book 01.94
Page
(in Version
01.94)
Page
(in new
Version)
Subjects (major changes since last revision)
220 11 Version 1.2
220 11 P-DIP-40 package not further available
224, 227,
16, 19, 36 Motorola Mode not available
243
249 40 Figure (Initializing the … 4096-kHz Device Clock) corrected
– 56 Abs. Max. Ratings: I
59 t
59 t
60 t
–60t
= 20 ns
WD min.
= 15 ns
s min.
= 20 ns, t
SS8 min.
= 100 ns added
SPL min
.
SH4 max.
defintion
LPD
= t
− 10 ns + t
CP4
CP4H
– 66 Appendix: Design sheets added
Edition 02.96
This edition was realized using the software system FrameMaker
Published by Siemens AG,
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Kommunikation, Balanstraße 73,
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©
Siemens AG 1996.
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.
PEB 2445
Table of Contents Page
1Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
1.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
1.2 Pin Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
1.3 Pin Definitions and Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
1.4 Functional Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
1.5 Device Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
1.6 System Integration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
2 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
2.1 Basic Functional Principles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
2.2 Microprocessor Interface and Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
3 Operational Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
3.1 Reset State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
3.2 Initialization Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
3.3 Operation with a 4096-kHz Device Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
3.4 Standby Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
4 Detailed Register Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41
4.1 Mode Register (MOD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41
4.2 Status Register (STA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
4.3 Conference Status Register (CST) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
4.4 Conference Mask Register (CMR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
4.5 Indirect Access Register (IAR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
4.6 Indirect Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53
4.6.1 Configuration Register (CFR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53
4.6.2 Clock Shift Register (CSR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54
5 Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56
5.1 DC Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56
5.2 Capacitances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57
5.3 AC-Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57
5.3.1 Microprocessor Interface Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57
5.3.1.1 Intel Bus Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57
5.3.2 PCM Interface Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59
5.3.3 Clock and Synchronization Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60
Semiconductor Group 3 02.96
PEB 2445
Table of Contents Page
6 Package Outlines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65
7 Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .66
7.1 Initialization for Conferencing in a PBX . . . . . . . . . . . . . . . . . . . . . . . . . . . . .66
7.2 Programming a Conference in a PBX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .67
7.3 Programming Procedure for Switching TS’s . . . . . . . . . . . . . . . . . . . . . . . . .68
7.4 Programming Procedure for a PBX Conference . . . . . . . . . . . . . . . . . . . . . .69
IOM®, IOM®-1, IOM®-2, SICOFI®, SICOFI®-2, SICOFI®-4, SICOFI®-4µC, SLICOFI®, ARCOFI
ARCOFI
SICAT
MUSAC
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®
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®
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™
-A, FALC™54, IWE™, SARE™, UTPT™, ASM™, ASP™ are trademarks of Siemens AG.
2
2
C-system provided the system confor ms to the I2C specifications defined by Philips. Copyright Philips 1983.
C components conveys a license under the Philips’ I2C patent to use the components in
®
, ARCOFI®-BA,
Semiconductor Group 4 02.96
PEB 2445
Overview
1Overview
A Complete Family of Efficient Solutions
If the issue is digital s witching and con feren cing, th e solut ion is fl exibil ity, cap acity, and
economy.
Siemens Semiconductor offers the most economical answer to all conceivable
applications in this field. Our complete family of switching network devices satisfies even
the most rigorous switching demands.
A Complete Family of Efficient Solutions
Take our MTSC (Memory Time Switch CMOS) PEB 2045 with a switching capability of
512 incoming PCM channels to 256 outgoing PCM chann els. It has the perfect size to
economically build medium sized switches. The design of a non-blocking switch for 512
PCM channels is possible with a simple parallel configuration with a second MTSC.
If you need a non-block ing switch fo r up to 256 c hannels, we o ffer a small er version of
the MTSC, the MTSS (Memory Time Switch Small) PEB 2046. And the MTSL
(Memory Time Switch Large) PEB 2047, the largest in our family, is capable of
switching 1024 PCM channels.
Siemens also supplies the best solution for conferencing, our MUSAC (Multipoint
Switching and Conferencing Unit) PEB 2245 performs the complete switching
functions of the MTSC, and offers a signal processor for handling up to 64 conferencing
channels in any combination. The input and output channels can also be attenuated
individually to achieve best transmission quality.
The MUSAC-A (Multipoint Switching and Conferencing Unit) PEB 2445 is an
upward compatible device to the MTSC and MUSAC. It offers in addition the attenuation
and amplification of every time slot.
Pin compatible device allow simplicity in hardware and software design. To allow for
more flexibility, the PCM data rate can be 2, 4, or 8 Mbit/s – configurable also for mixed
use.
Semiconductor Group 5 02.96
The figure below shows the general architecture of a digital exchange.
PEB 2445
Overview
Figure 1
General Exchange Architecture
System Background
Digital exchanges p ut calls through by newly arranging the spe ech signals coded w ith
8-bit words (PCM time-slots). The code words are transmitted serially on PCM lines. The
sampling frequency of 8 kHz produces PCM frames with a duration of 125 µs. The
transmission rate on the line determi nes how many co de words (spee ch chann els) can
be accommodated within a sampling period. With a data rate of 2048 kbit/s for example,
there are 32 time-slots of 8 bits each. 4 lines with a data rate of 8192 kbit/s have a
transmission capacity of 512 channels.
Semiconductor Group 6 02.96
PEB 2445
Overview
An overview on the complete switching and conferencing IC-family is shown in the
following table:
Table 1
Complete Switching and Conferencing IC Family
MTSC
PEB 2045
Switching
capacity
(time-slots)
Input/output
lines
PCM-data rate
(Mbit/s)
Clock rate
(MHz)
Conferencing
Attenuation
PRI/T1 mode
Fractional T1
data bundling
µ
C access read read yes yes
Multipoint
switching
Power (mW)
max.
consumption
typ
Package
1)
in definition
512 × 256 256 × 256 1024 × 512 1024 × 1024 512 × 256 512 × 256 256 × 256 256 × 256
‘16/8 ‘8/8 ‘16/8 ‘16/8 ‘16/8 ‘16/8 ‘8/8
2/4/8 +
mixed mode
4.096
8.192
yes yes yes
50 50 100 170 100 100 50 50
P-DIP-40
P-LCC-44
MTSS
PEB 2046
2 2/4/8 +
4.096
8.192
P-DIP-40
P-LCC-44 P-LCC-44 P-LCC-44 P-LCC-44 P-LCC-44 P-LCC-44 P-LCC-44
MTSL
PEB 2047
mixed mode
4.096
8.192
yes yes 128-Kbit/s
MTSL 16
PEB 2047-16
2/4/8/16 +
mixed mode
4.096/8.192
16.384
MUSAC
PEB 2245
2/4/8 +
mixed mode
4.096
8.192
64 channels 64 channels
64 channels
3/6/9 dB
yes yes
MUSAC-A
PEB 2445
2/4/8 +
mixed mode
4.096
8.192
all channels
– 4 to 12 dB
EPIC-1
PEB 2055
SLD/IOM/
PCM
up to 8 up to 8
up to
8.192
channel
EPIC-S
PEB 2054
‘6/6
IOM/PCM
up to
8.192
128-Kbit/s
channel
Semiconductor Group 7 02.96
PEB 2445
Overview
Conferencing
An important task in PCM voice handlin g is conferencing. I.e. several subscribers of a
digital PBX system would like to arrange a conference call. This task will be done in the
central switching network. Mo dern switching IC like the MUSAC-A fulfill this important
task in a cost effective way in the central switching unit. A powerful on chip Digital
Signaling Processor handles this requirement.
Definite time-slots will be added together to one subscriber signal. In order to ensure an
acceptable speech quality and reduce of echo and ‘singing’ problems, the input and
output channels have to be attenuat ed individually. Additionally , input signals below a
threshold programmable to d ifferent leve ls are disregarded . Another trick to les sen the
risk of instability in multiparty conferences is to i nve rt every second voice channel. Odd
and even channels are substracted from one other.
TM
Conferencing with the MUSAC
-A
Conferencing means that PCM data of several subscribers are processed such that
each subscriber receives the contribution of the PCM data transmitted by all participants
of the conference. Except the data transmitted by himself.
Each subscriber is qualified by an input channel which corresponds to a certain input line
and time-slot of the MUSAC-A, and an output channel w hich corresponds to a certain
output line and time-slot of the MUSAC-A.
The data flow through the MUSAC-A in case of conferencing is illustrated in figure 2.
Semiconductor Group 8 02.96
PEB 2445
Overview
Figure 2
Data Flow through the MUSAC-A in Case of Conferencing
Semiconductor Group 9 02.96
PEB 2445
Overview
The PCM samples of each input channel first pass through an input processi ng stage.
In this stage, an input attenuation level (0, 3, 6 or 9 dB) and a noise suppression
threshold can be programmed individually for each channel. Following the input
processing the PCM data is expanded according to the A- or µ-law enc oding rule s and
written to the Data Memory (DM). Addit ionally the PCM data of each input channel is
added to the Conference Sum Memory (CSM). The DM location (1 out of 64) is specified
by the Conference Control Address (CCA) and the CSM location (1 out of 21) is specified
by the conference number when writing to the Conference Control Memory (CCM).
The PCM data then passes through a subs tractor stage such t hat the resulting ou tput
channel for a given su bscriber con tains the c ontribution o f all th e other channels in the
conference except its own. Finally the PCM data is forwarded to the output channel after
PCM compression and an optional output attenuation of 3 dB.
Attenuation
Attenuation is a new requiremen t for PBX switching systems. The purp ose is to avoid
echo and noise problems on a PBX network for voice con nections with access to the
public network. Further a certain loudness rating on a definite point for different terminals
and phones could be fixed (see figure 3).
Figure 3
Semiconductor Group 10 02.96
Multipoint Switching and Conferencing
PEB 2445
Unit - Attenuation
TM
MUSAC
Version 1.2 CMOS IC
1.1 Features
Switching
• Time/space switch for 2048-, 4096- or 8192-kbit/s
PCM systems
• Switching of up to 512 incoming PCM channels to up
to 256 outgoing PCM channels
• 16 input and 8 output PCM lines
• Different kinds of modes (2048, 4096, 8192 kbit/s or
mixed mode)
• Configurable for a 4096- and 8192-kHz device clock
• Tristate function for further expansion and tandem operation
-A
P-LCC-44
Attenuation and Amplification
• Attenuation and amplification of every time-slot
• Attenuation range from 0 to 12 dB
• Amplification range from 0 to 4 dB
Type Version Ordering Code Package
PEB 2445-N V1.2 Q67100-H6298 P-LCC-44 (SMD)
Semiconductor Group 11 02.96
PEB 2445
Overview
Conference Mode
• Up to 64 conference channels in any combination
• Up to 21 independent conferences simultaneously (3 subscribers)
• Programmable attenuation (0/3/6/9 dB) on each input channel
• Programmable attenuation (0/3 dB) on each output channel
• Programmable PCM-level adaption (attenuation or amplification) of up to 64 channels
• Programmable noise suppression (four thresholds)
• Conference overflow handling
• Tone insertion capability
• A-law / µ-law compatible
• Compatible with all kinds of PCM-byte formats
Multipoint Switching
• Multiple independent LAN’s within one PBX
• Multiplexing of up to 64 channels
• 64-kbit/s channels
General
• 8-bit µP interface
• Single + 5 V power supply
• Advanced low power CMOS technology
• TTL-compatible inputs/outputs
• Upward compatible to MTSC and MUSAC
General Description
The MUSAC-A is an upward co mpatible device to the reliable compo nents MTSC and
MUSAC. Additionally to th e stand ard MUSAC fea tures switc hing a nd confe renc ing, the
MUSAC-A supports enlarged attenuation functions.
Every time-slot is freely pro gramm abl e i n 1-d B step resolutions to an a ttenu atio n ra nge
from 0 to 12 dB and amplified from 0 to 4 dB.
With enlarged attenuation functions to every time-slot the MUSAC-A fulfills the ability for
new requirements. I.e. different PBX terminals could be adap ted to a certain reference
point from the private network to the public network.
Semiconductor Group 12 02.96
1.2 Pin Configuration
(top view)
PEB 2445
Overview
P-LCC-44
Semiconductor Group 13 02.96
1.3 Pin Definitions and Functions
PEB 2445
Overview
Pin No.
P-LCC
1
6INT
Symbol Input (I)
Output (O)
V
SS
I Ground (0 V)
OD
open drain
Function
Interrupt Request: The signal is activated when a
conference overflow is detected. The microprocessor may determine the specific conference in overflow by reading the conference status register
(CST). The interrupt is maskable. INT
is an open
drain output, thus a ‘wired-or’ combination of interrupt request outputs of several MUSAC-As is possible (a pull up resistor is necessary).
3SP I Synchronization Pulse: The MUSAC-A is syn-
chronized relative to the PCM system via this line.
4
7
9
11
13
14
15
16
17
18
19
IN1
IN5
IN9
IN13
IN14
IN15
IN10
IN11
IN6
IN7
IN2
I
I
PCM-Input Ports: Serial data is received at these
lines at standard TTL levels.
I
I
I
I
I
I
I
I
I
5
8
10
12
IN0/TSC0
IN4/TSC1
IN8/TSC2
IN12/TSC3
I/O
I/O
I/O
I/O
PCM-Input Port / Tristate Control: In standard
configuration these pins are used as input lines, in
primary access configuration they supply control
signals for external devices.
20 IN3/DCL I/O PCM-Input Port / Data Clock: In standard config-
uration IN3 is the PCM-input line 3, in primary
access configuration it provides a 2048-kHz data
clock for the synchronous interface.
21
28
A0
A1
I
I
Address for Direct Register Access:
These pins are only active if a demultiplexed
µP-interface mode is selected.
If A1 is not connected it will be set to ground inter-
nally.
Semiconductor Group 14 02.96
1.3 Pin Definitions and Functions (cont’d)
PEB 2445
Overview
Pin No.
P-LCC
Symbol Input (I)
Output (O)
Function
22 CS I Chip Select: A low level selects the MUSAC-A for
a register access operation.
23
V
DD
24 RD
I Supply Voltage: 5V ± 5%
I Read: This signal indicates a read operation and is
internally sampled only if CS
is active. The
MUSAC-A puts data from the selected internal reg-
25 WR
ister on the data bus with the falling edge of RD
is active low (Siemens/Intel bus mode).
RD
I Write: This signal initiates a write operation. The
WR
input is internally sampled only if CS is active.
.
In this case the MUSAC-A loads an internal regis-
ter with data from the data bus at the rising edge of
. WR is active low (Siemens/Intel bus mode).
WR
2ALE I Address Latch Enable: In the Intel type multi-
plexed
µP-interface mode a logical high on this line indi-
cates an address of a MUSAC-A internal register
on the external address/data bus. In the Intel type
demultiplexed.
V
µP-interface mode this line is hardwired to
SS
, in
the demultiplexed Motorola type µP-interface
mode it should be connected to
V
DD
.
If ALE is not connected it will be set to ground internally.
26
27
29
30
31
32
33
34
Semiconductor Group 15 02.96
AD0
AD1
AD2
AD3
AD4
AD5
AD6
AD7
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
Address Data Bus: If the multiplexed
address/data µP-interface bus mode is selected
these pins transfer data and addresses between
the µP and the MUSAC-A.
If a demultiplexed mode is used, these bits interface with the system data bus.
1.3 Pin Definitions and Functions (cont’d)
PEB 2445
Overview
Pin No.
P-LCC
35
36
37
38
40
41
42
43
Symbol Input (I)
Output (O)
OUT7
OUT6
OUT5
OUT4
OUT3
OUT2
OUT1
OUT0
O
O
O
O
O
O
O
O
Function
PCM-Output Port: Serial data is sent by these
lines at standard CMOS- or TTL levels. These pins
can be tristated.
39 RES I Reset: A high signal on this input forces the
MUSAC-A into reset state. The minimum pulse
length is four clock periods. If this pin is not connected it will be set to ground internally.
44 CLK I Clock: 4096- or 8192-kHz device clock
Semiconductor Group 16 02.96
1.4 Functional Symbols
PEB 2445
Overview
Figure 4
Functional Symbol for the Standard Configuration
Figure 5
Functional Symbol for the Primary Access Configuration
Semiconductor Group 17 02.96
PEB 2445
Overview
1.5 Device Overview
The Multipoint Switching and Conferencing Unit (MUSAC-A) combines a time switch unit
(MTSC) and a powerful signal processor on one chip. The MUSAC-A enhances the
capabilities of a PBX by supporting teleconferencing and multipoint data communication
over voiceband channels. Digital signal processing techniques are used to implement
the conferencing algorithms. Up to 64 channels of the 512 incoming PCM channels may
be manipulated by the signal processor and output to any of 256 outgoing PCM
channels. All functions are programmed and controlled via an 8-bit standard µP interface
(Intel type).
The MUSAC-A is fabricated using the advanced CMOS technology from SIEMENS and
is mounted in a P-LCC-44 package. Inputs and outputs are TTL-compatible.
The PEB 2445 is pin and register compatible to the PEB 2045.
In addition, it includes the following features:
• Conference Unit
• Programmable attenuation for each output channel in the range of − 4 dB up to 12 dB.
• The attenu ations of the outputs and the a ttenuations in the conference u nit can be
selected independent of one another.
Figure 6
Block Diagram of the PEB 2445
Semiconductor Group 18 02.96
PEB 2445
Overview
1.6 System Integration
Conferencing
The MUSAC-A is designed t o connect any of the 512 PCM-input channels to any of
256 output channels. Any inp ut channel up to a total number of 64 c an be handled in
21 independent conferences simultaneously. Any conference combination from
3 subscribers in 21 conferences up to 64 subscribers in only one conference is possible.
In order to ensure an acceptable speech quality and to reduce echo and ‘singing’
problems, the input channels can be attenuated individually by 0, 3 dB, 6 dB or 9 dB and
the output channels by 0 or 3 dB; additionally, input signals below a threshold
programmable to four different levels are disregarded (see chapter 4.5).
To lessen the risk of instability in multiparty conferences the voice signal from every
second channel can be inv erted so that disturban ce signals in odd and ev en channels
are subtracted from one another.
If more capacity is needed, several devices can be connected. By connecting the
16 PCM-input lines in parallel to two MUSAC-As, a non-blocking switching matrix for
512 subscribers can be implemented: 128 input channels can be selected for up to
42 independent, simultaneous conferences. Figure 7 shows such an arrangement. Due
to the tristate capability of the MUSAC-A larger switches with conferencing capability can
be easily formed.
Figure 7
Memory Time Switch 16/16 for a Non-Blocking 512 Channel Switch
with Conferencing Capability
Semiconductor Group 19 02.96
PEB 2445
Overview
Figure 8 shows the architecture of a primary access board with common channel
signaling using four CMOS devices.
Figure 8
Architecture of a Primary Access Board
Semiconductor Group 20 02.96
PEB 2445
Overview
Multipoint Switching
In a multipoint confi guration the communication between di fferent stations is done by
using a common media. In a PBX system this can be achieved by connecting all stations
to one (or more) time-slots and transmitting the information back. Multipoint-switching is
a special form of conferencing for data communication. In contrast to audio conferences
terminals broadcast data to the MUSAC-A which are only ‘or-connected’. That is, at each
bit time, the ‘conference sum’ is ‘1’ if the input of one or more terminals is ‘1’; otherwise,
the result is ‘0’. A simple example of such a system using Siemens VLSI switching
devices is shown in figure 9.
ISDN subscribers are connected via line cards and PCM highways to a multipoint
switching matrix. The data from different terminals are summed up in the multipoint
switching matrix and tran smitted back to all stations. The switching matrix is build by
using just one MUSAC-A. Every combination of subscribers may be switched to the
same transport media (time-sl ot), in this way enabli ng a number of pow erful multipoint
communication systems.
Figure 9
Multipoint System Configuration for ISDN Subscribers
Semiconductor Group 21 02.96
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