psf21911 ETC-unknow, psf21911 Datasheet - Page 68

• Manufacturer Part Number: psf21911
• Description: Isdn Echocancellation Circuit Terminal Applications Iec-q
• Manufacturer: ETC-unknow

Semiconductor Group
TL
BBD0/1 Binary “0s” or “1s” detected in the B- and D-channels
Timers
The start of timers is indicated by TxS, the expiry by TxE. The following table 14 shows
which timers are used by the U-transceiver:
Table 14
Timer
T1
T7
T11
T12
T13
T14
Wake-up signal received from the LT
The U-transceiver is requested to start an activation procedure. The TL-
criterion is fulfilled when 12 consecutive periods of the 10-kHz wake-up tone
were detected.
When in the “Pending Timing” state and automatic activation after reset is
selected (NT-AUTO mode), a recognition of TL is assumed every time the
“Pending Timing” state has been entered from the “Test” state (caused by C/I
code DI). This behavior allows the U-transceiver to initiate one single
activation attempt after having been reseted.
This internal signal indicates that for 6-12 ms, a continuous stream of binary
“0s” or “1s” has been detected. It is used as a criterion that the receiver has
acquired frame synchronization and both its EC- and EQ-coefficients have
converged. BBD0 corresponds to the signal SL2 in the case of normal
activation and BBD1 corresponds to the internally received signal SN3 in case
of an analog loop back in the NT-mode.
Timers
Duration (ms) Function
15000
9
5500
15000
0.5
40
Supervisor for start-up
Hold time
TN-transmission
Supervisor EC-converge
Frame synchronization
Hold time
68
State
Receive reset
Alerting
EC-training
Pend. receive
reset
Pend. timing
U-Transceiver
PSB 21911
PSF 21911
11.97