PEB2445NV1.2 Lantiq, PEB2445NV1.2 Datasheet - Page 24

• Manufacturer Part Number: PEB2445NV1.2
• Manufacturer: Lantiq

Specifications of PEB2445NV1.2

• Lead Free Status / Rohs Status: Supplier Unconfirmed

512 PCM- input channels to any of 256 output channels. Any input channel up to a total
number of 64 can 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. Not more than 8 subscribers should be connected to a
single conference, however, in order to ensure an acceptable speech quality. It can be
improved by selecting an additional attenuation and activating the noise suppression:
The input channels can be attenuated by 0, 3 dB, 6 dB or 9 dB and the output channels
by 0 or 3 dB. Input signals below a threshold programmable to four different levels are
disregarded.
The input information of a complete frame is stored in the on-chip 4-Kbit Speech Memory
(SM). The incoming 512 channels of 8 bits each are written in sequence into fixed
positions in the SM with a repetition rate of 8 kHz. Additionally, in the second half of the
frame the 64 conference output channels of 8 bit each are written into the SM. The
memory access is normally controlled by the input counter in the timing control block
when writing into the SM but by the conference unit when writing the conference output
channels. The read access is independent of the write access, so that both input and
conference output channels can be read at any time.
For outputting, the Connection Memory (CM) is read in sequence. Each location in the
CM points to a location in the Speech Memory. Before the byte in this SM location is read
into the current output time-slot, it can be attenuated. The attenuation takes care of the
compressed data format (A-law, -law). The attenuations for all 256-output channels are
stored in the CM and can be chosen between – 4 dB (amplification) to 12 dB
(attenuation). The read access of the CM is controlled by the output counter also
contained in the timing control block. In addition, in the first half of the frame the input
channels connected to a conference are read in sequence by the Conference Unit (CU).
All connections are set up by an external controller which programs the Connection
Memory (CM) and the Conference Control Memory (CCM) using the microprocessor
interface. The CM address corresponds to one particular output time-slot and line
number. The contents of this CM-location points to a particular input time-slot and line
number in the transparent mode. In the conference mode or multipoint switching mode
it contains the conference address and points to a conference output location in the SM
instead. The same conference address is used to access the CCM. The parameters
2.1
The MUSAC-A is a memory time switch device for a PCM PBX system, offering a variety
of additional features like multipoint switching, conference calls, programmable noise
suppression and attenuation. The MUSAC-A works either in standard configuration for
usual switching applications or in the primary access configuration, where it realizes,
together with the PEB 2035 (ACFA) and the PEB 2235 (IPAT), the system interface for
up to four primary multiplex access lines. In both configurations the conference and
multipoint switching capability can be used.
The block diagram is shown in figure 11. The MUSAC-A is designed to connect any of
Semiconductor Group
Basic Functional Principles
24
Functional Description
PEB 2445
02.96