PEB2096 SIEMENS [Siemens Semiconductor Group], PEB2096 Datasheet - Page 16

• Manufacturer Part Number: PEB2096
• Description: Octal Transceiver for UPN Interfaces OCTAT-P
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

downstream receiver (e.g. ISAC-P TE) gets enough pulses for a reliable clock extraction
(flat continuous power density spectrum is provided) and no periodic patterns appear on
the line.
The scrambling is in accordance with CCITT V.27.
The coding technique used on the U interface is a half-bauded AMI code (with a 50 %
pulse width). A logical ‘0’ corresponds to a neutral level, logical ‘1’ are coded as alternate
positive and negative pulses. Code violation (CV) is caused by two successive pulses
with the same polarity.
See figure 6. The AMI coding includes always the data bits going on the U
in one direction. Thus there is a separate AMI coding unit for data downstream and one
for data upstream.
Figure 6
AMI Coding on the U
From this reference (CV = bit 1), bit 3 of the superframe is the service channel bit S. This
S-channel bit is transmitted once in each direction in every fourth burst repetition period.
Hence the duplex S channel has a data rate of 1 kbit/s. It conveys test loop control
information from the LT to the TE/PT and reports of transmission errors from the TE/PT
to the LT. Bit 2 and bit 4 of the superframe are the T bits. This 2 kbit/s channel is
accessible via the C/I channel and may be used to carry the “available”/“blocked”
information sent by the D-channel arbiter of the PEB 20550, ELIC.
It is allowed to add a DC balancing bit to the burst, in order to decrease DC offset voltage
on the line after transmission of a CV in the M-bit position. The OCTAT-P transmits this
DC balancing bit when transmitting INFO 4 and when line characteristics indicate
potential decrease in performance.
The OCTAT-P scrambles B-channel data on the U
Semiconductor Group
PN
Interface
16
PN
interface in order to ensure that the
PN
PEB 2096
interface
01.96