PEF2091 Siemens Semiconductor Group, PEF2091 Datasheet - Page 244

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

Semiconductor Group
6.8.5
Activating the U-interface only partially is a requirement specified by the CNET. The
S-interface remains deactivated.
When activating partially from the LT side, the exchange has two options:
First, in case the C/I-command DC is not issued after the partial activation is complete,
the exchange has to issue AR before a terminal initiated complete activation request is
accepted (see 6.8.7, case 1). This allows the exchange to retain full control, even in case
of terminal initiated activation requests.
Secondly the exchange can issue DC after UAI has been received. This allows the
terminal to activate the S-interface independently of the exchange (see 6.8.7, case 2). In
this case the exchange has no control of the S-interface activation procedure.
<–––––
–––––>
<–––––
<–––––
6.8.6
When U is already active, the S-interface can be activated either by the exchange or the
terminal. The first case is described here, the second in the next section.
<–––––
–––––>
<–––––
–––––>
–––––>
<–––––
NT
C/I DC
C/I DI
C/I PU
C/I DC
NT
C/I DC
C/I DI
C/I AR
C/I AR
C/I AI
C/I AI
Partial Activation (U Only)
Complete Activation Initiated by LT with U Active
(1111
(1111
(0111
(1111
(1111
(1111
(1000
(1100
(1100
(1100
B
B
B
B
B
B
B
B
B
B
)
)
)
)
)
)
)
)
)
)
LT
C/I DC
C/I DI
C/I UAR
C/I AR
C/I ARM
C/I UAI
[C/I DC
LT
C/I UAR [DC]
C/I UAI
C/I AR
C/I AR
C/I UAI
C/I AI
(1111
(1111
(0111
(1000
(1001
(0111
(1111
(0111
(1000
(1000
(0111
(1100
244
B
B
B
B
B
B
B
B
B
B
B
B
)
)
)
)
)
)]
)
)
)
)
)
)
<––––– ; Initial state is "Deactivated"
–––––>
<––––– ; Start partial activation
–––––> ; Activation proceeds
–––––> ; :
–––––> ; Partial activation complete
<––––– ;
<––––– ; U only is activated
–––––> ;
<––––– ; Start complete activation
–––––> ; Activation proceeds
–––––>
–––––> ; Activation complete
;
;
;
;
Exchange retains no
control of S-interface
activation
[exchange retains no
control]
Confirm that terminal is
active
Data Sheet 01.99
Programming
PEB 2091
PEF 2091