PEF2091 Siemens Semiconductor Group, PEF2091 Datasheet - Page 163

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

4.4.3.2
C/I-Commands
AI
AR
ARL
DI
DIN = 0
DT
EI1
Semiconductor Group
Transition Criteria in NT Modes
Activation Indication
The S-transceiver issues this indication to announce that the S-receiver is
synchronized. The IEC-Q informs the LT side by setting the "ACT" bit to "1".
Activation Request
INFO1 has been received by the S-transceiver or the Intelligent NT wants to
activate the U-interface. The IEC-Q is requested to start the activation
process by sending the wake-up signal TN.
Activation Request Local Loop-back
The IEC-Q is requested to operate an analog loop-back (close to the
U-interface) and to begin the start-up sequence by sending SN1 (without
starting timer T1). This command may be issued only after the IEC-Q has
been reset by making use of the C/I-channel code RES or a hardware reset.
This assures that the EC- and EQ-coefficients updating algorithms
converge correctly. The ARL-command has to be issued continuously as
long as the loop-back is required.
Deactivation Indication
This indication is used during a deactivation procedure to inform the IEC-Q
that timing signals are needed no longer and that the IEC-Q may enter the
deactivated (power-down) state. The DI-indication has to be issued until the
IEC-Q has answered with the DC-code.
Binary "0" polarity on DIN
This asynchronous signal requests the IEC-Q to provide IOM
Hereafter, binary "0s" in the C/I-channel (code TIM "0000" or any other code
different from DI "1111") keep the IOM
Data Through
This unconditional command is used for test purposes only and forces the
IEC-Q into a state equivalent to the "Transparent" state. The far-end
transceiver is assumed to be in the same condition. Note however that in
this case the C/I indication (initiated by the IEC-Q) depends on the state of
the far-end transceiver and is not specified.
Error Indication 1
The S-transceiver indicates an error condition on its receiver side (loss of
frame alignment or loss of incoming signal). The IEC-Q informs the LT side
by setting the ACT-bit to "0" thus indicating that transparency has been lost.
163
®
-2 interface active.
Operational Description
Data Sheet 01.99
PEB 2091
PEF 2091
®
-2 clocks.