peb3456 Infineon Technologies Corporation, peb3456 Datasheet - Page 87

• Manufacturer Part Number: peb3456
• Description: Channelized T3 Termination With Ds3 Framer, M13 Multiplexer, T1/ E1 Framers And 256 Channel Hdlc/ppp Controller
• Manufacturer: Infineon Technologies Corporation

LOS detection and recovery conditions are set by a flag RFMR.LOSR and the two
parameters PCD and PCR.
Detection
’Loss of Signal’ alarm will be generated, if the incoming data stream has no pulses (no
a logical zero octet on receive data inputs. The number N can be set via register PCD
and is calculated as 8*(PCD+1).
4.6.4
4.6.4.1
Generation
The alarm indication signal is an all one unframed signal and will be transmitted if
enabled via bit TCMDR.XAIS.
Detection
The detection of AIS is done, if 2 or less ’0’s are detected in a multiframe. This condition
is flagged by bit FRS.AIS. AIS detection can also only be enabled in asynchronous state
by bit RFMR0.AIS3. In this case AIS is indicated if three or less zeros within a time
interval of 12 frames (in SF mode), or if five or less zeros within a time interval of 24
frames (ESF mode) are detected in the received bit stream.
4.6.4.2
The TE3-CHATT can be programmed to satisfy the different definitions for detecting
Loss of Signal (LOS) alarms in ITU-T G.775 and AT&T TR54016. Loss of signal is
indicated by a flag in the receive framer's status register (FRS.LOS). In addition, a ’Loss
of Signal Status’ interrupt vector is generated, if not masked.
’1’) for a certain number N of consecutive bits. ’No pulse’ in the receive interface means
Recovery
The recovery procedure starts after detecting a logical ’1’ in the received bit stream. The
value via register PCR defines the number of pulses, which must occur during the time
interval 8*(PCD+1), to clear the LOS alarm.
Additionally, if selected via RFMR.LOSR, any pulse density violation resets the
measurement interval. I.e. in addition to the basic pulse density required for recovery, a
density of at least N ‘1’s in every N+1 octets (0 < N < 24) is required during 8*(PCD+1)
bit intervals.
Data Sheet
Common Features for SF and ESF
AIS (Blue Alarm) Generation/Detection
Loss of Signal (Red Alarm) Detection
87
Functional Description
PEB 3456 E
05.2001