psf21911 ETC-unknow, psf21911 Datasheet - Page 65

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

2.5.7.3
C/I-Commands
AI
AR
ARL
DI
DIN = 0
DT
EI1
RES
Semiconductor Group
Activation Indication
The S-transceiver issues this indication to announce that the S-receiver is
synchronized. The U-transceiver 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 U-transceiver is requested to start the activation
process by sending the wake-up signal TN.
Activation Request Local Loop-back
The U-transceiver 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 U-transceiver has been
reset by making use of the C/I-channel code RES or a hardware reset. This
assures that the EC- and EQ-coefficient 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 U-
transceiver that timing signals are needed no longer and that the U-transceiver
may enter the deactivated (power-down) state. The DI-indication has to be
issued until the U-transceiver has answered with the DC-code.
Binary “0” polarity on DIN
This asynchronous signal requests the U-transceiver to provide IOM clocks.
Hereafter, binary “0s” in the C/I-channel (code TIM “0000” or any other code
different from DI “1111”) keep the IOM-2 interface active.
Data Through
This unconditional command is used for test purposes only and forces the U-
transceiver into a state equivalent to the “Transparent” state. The far-end
transceiver is assumed to be in the same condition.
Error Indication 1
The S-transceiver indicates an error condition on its receive side (loss of frame
alignment or loss of incoming signal). The U-transceiver informs the LT-side
by setting the ACT-bit to “0” thus indicating that transparency has been lost.
Reset
Unconditional command which resets the whole chip; especially the EC- and
EQ-coefficients are set to zero.
Inputs to the U-Transceiver
65
U-Transceiver
PSB 21911
PSF 21911
11.97