PEB2245N-V12 Infineon Technologies, PEB2245N-V12 Datasheet - Page 21

• Manufacturer Part Number: PEB2245N-V12
• Description: IC SWITCHING/CONFER MULTI 44PLCC
• Manufacturer: Infineon Technologies
• Series: MUSAC™r

Specifications of PEB2245N-V12

• Function: Multipoint Switching and Conferencing
• Interface: PCM
• Voltage - Supply: 5V
• Current - Supply: 12mA
• Power (watts): 100mW
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 44-PLCC
• Includes: Clock Shift, Space Switch Mode, Time and Space Switch, Tristate Function
• Lead Free Status / RoHS Status: Request inventory verification / Request inventory verification
• Number Of Circuits: -
• Other names: PEB2245N-V12; PEB2245N-V12IN

A tone to be inserted into a conference is handled as an additional conference subscriber using any
input PCM channel (access to CCM) but without assigning an output time-slot (no access to CM).
Multipoint switching is a special form of conferencing for data communication. In the multipoint
switching mode several terminals are connected together. Normally only one should transmit at a
time; its signal is distributed to the other terminals. For collision detection purposes all input signals
are summed up to construct the output signal. In contrast to audio conferences terminals broadcast
data to the MUSAC 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”. The data memory, the
subtractor, the linearization and attenuation are of no use in this mode. The general procedure is the
same as for conferencing.
The chip architecture makes it possible to decrease the delay between incoming and outgoing PCM
channels. The processed input samples are transmitted either in the same frame or in the next
frame at the latest.
Definitions
Preparation of the Input Data (Input Buffer)
The PEB 2245 works in 2048-, 4096- or 8192-kbit/s PCM systems. The frame frequency is 8000 Hz
in all 3 types of systems. Therefore a frame consists of 32, 64 or 128 time-slots of 1 byte each,
respectively. In order to fill the speech memory, which has a fixed capacity of 512 channels, either
16-, 8- or 4 input lines are necessary, respectively. Thus, in 4- and 8-MHz systems only some of the
16 input lines can be used.
Moreover, the PEB 2245 can also work with two different input data rates simultaneously. In this
case some of the PCM-input lines operate at one data rate, while others operate at another.
Table 2 states how many input lines are operating at the different data rates for all possible input
data rate combinations. In the following they will be referred to as input modes. The input mode the
PEB 2245 is actually working in has to be programmed into the mode register, bits MI1, MI0, MO1,
MO0. In chapter 4.1 you will find a complete description which input line is connected to which
system, for each of the input modes.
Semiconductor Group
The PEB 2245 works with either an 8192-kHz clock or a 4096-kHz clock. Henceforth, the
respective clock periods are referred to as
The bits of a time-slot are numbered 0 through 7. Bit 0 (MSB) of a time-slot is the first bit to be
received or transmitted by the MUSAC, bit 7 (LSB) the last.
t
CP8
21
and
t
CP4
.
PEB 2245