PEF2091 Siemens Semiconductor Group, PEF2091 Datasheet - Page 167

• Manufacturer Part Number: PEF2091
• Description: ICs for Communications(ISDN Echocancellation Circuit)
• Manufacturer: Siemens Semiconductor Group

Timers
The start of timers is indicated by TxS, the expiry by TxE. The Table 30 shows which
timers are used by the IEC-Q in NT mode:
Table 30
Timer
T1
T7
T11
T12
T13
T14
4.4.3.3
Signals and indications are issued on the C/I Channel and on the U-interface (predefined
U-signals).
C/I Indications
AI
AIL
AR
ARL
Semiconductor Group
Output Signals and Indications in NT Modes
Activation Indication
The IEC-Q has established transparency of transmission in the direction
IOM
INFO4 and to achieve transparency of transmission in the direction IOM
to S/T-interface.
Activation Indication Loop-back
The IEC-Q has detected ACT = 1 while loop-back 2 is still established. In an
NT1, the S-transceiver is requested to send INFO4 (if a transparent
loop-back 2 is to be implemented) and to keep loop-back 2 active.
Activation Request
The IEC-Q has synchronized on the incoming signal. In an NT1, the
S-transceiver is requested to start the activation procedure on the
S/T-interface by sending INFO2.
Activation Request Loop-back
The IEC-Q has detected a loop-back 2 command in the EOC-channel and
has established transparency of transmission in the direction IOM
U-interface. In an NT1, the S-transceiver is requested to send INFO2 (if a
transparent loop-back 2 is to be implemented) and to operate loop-back 2.
Timers for NT State Machine
Duration (ms) Function
15000
40
9
5500
15000
0.5
®
-2 to U-interface. In an NT1, the S-transceiver is requested to send
Supervisor for start-up
Hold time
TN-transmission
Supervisor EC-converge
Frame synchronization
Hold time
167
Operational Description
State
Receive reset
Alerting
EC-training
Pend. receive
reset
Pend. timing
Data Sheet 01.99
PEB 2091
PEF 2091
®
-2 to
®
-2