PEF2091 Siemens Semiconductor Group, PEF2091 Datasheet - Page 125

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

4.3
The IEC-Q is designed to meet the newest standards of ANSI and ETSI regarding status
control. The following sections describe some of the most important protocols
implemented in the IEC-Q. They illustrate the interaction between the stations involved.
All information presented in this section is extracted from the state machines (see "State
Machines", page 145).
Table 28 shows all U-interface signals as defined by ANSI.
Table 28
1) Alternating
2) Must be generated by the exchange
3) Alternating
Semiconductor Group
Signal
SN3T
SL3
SL3T
TN
SP
SN0
SN1
SN2
SN3
TL
SL0
SL1
SL2
1)
1)
3)
2)
Layer 1 Activation and Deactivation
3 symbols at 10 kHz
3 single pulses of 12.5 s duration spaced by 1.5 ms, else no signal
U-Interface Signals
Synch. Word
no signal
no signal
present
present
present
present
present
present
present
present
(SW)
3
3
Superframe
Test Mode
NT –> LT
LT –> NT
no signal
no signal
present
present
present
present
present
absent
absent
absent
(ISW)
125
3
3
3
no signal
no signal
2B + D
normal
normal
1
1
1
1
0
0
3
3
Operational Description
Data Sheet 01.99
no signal
no signal
M-Bits
normal
normal
normal
normal
normal
PEB 2091
PEF 2091
1
1
1
3
3