PEF2091 Siemens Semiconductor Group, PEF2091 Datasheet - Page 155

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

DI
EI2
EI3
LSL
RSY
FJ
HI
UAI
ARM
INT
Semiconductor Group
Deactivation Indication
Idle code on the IOM
"Deactivated" state unless an activation procedure is started by the NT side.
Error Indication 2
EI2 is issued if the received ACT-bit is (0). The NT receiver indicates a loss
of signal or framing on the S/T-interface by setting the upstream ACT-bit to
(0). The IEC-Q remains in the "Transparent" state. After a signal level or
framing is detected again, the C/I-indication AI will be issued anew.
Error Indication 3
This indication is issued when the IEC-Q has not been able to activate
successfully (expiry of timer T1).
Loss of Signal Level
The IEC-Q has entered a failure condition after loss of signal level (LSUE).
Re-Synchronization indication after a loss of framing (LOF)
For EI3, LSL and RSY indication the LT side should react by applying the
C/I-channel code RES1 to allow the IEC-Q to enter the "Receive reset" state
and to reset the Receiver functions.
Frame Jump
This indication signals that either a data buffer overflow/underflow has been
detected or a phase jump of one of the IOM
has occurred. The FJ-code is issued for a period of 1.5 ms.
High Impedance
PFOFF is activated which means that the remote-power-feed circuit for the
subscriber line is turned off.
U-Activation Indication
The UAI-code signals that the line system is synchronized in both directions
of transmission (see also the input ACT = 1). Maintenance bits are
transmitted normally.
Activation Request Maintenance
Transmission of maintenance bits is possible.
Interrupt (Stand-alone mode only)
A level change on input pin INT triggers the transmission of this C/I code for
four successive IOM
details.
®
-2 frames. Please refer to "Interrupt", page 197 for
®
-2-interface. Normally the IEC-Q stays in the
155
®
-2-timing signals DCL or FSC
Operational Description
Data Sheet 01.99
PEB 2091
PEF 2091