psf21911 ETC-unknow, psf21911 Datasheet - Page 70

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

Semiconductor Group
INT
PU
Signals on U-Interface
The signals SNx, TN and SP transmitted on the U-interface are defined in Table 22 on
page 100.
The polarity of the transmitted ACT-bit is as follows:
The polarity of the issued SAI-bit depends on the received C/I-channel code: DI and TIM
leads to SAI = 0, any other C/I-code sets the SAI-bit to 1 indicating any activity on the
S/T-interface.
2.5.7.5
The following states are used:
Alerting
The wake-up signal TN is transmitted for a period of T11 either in response to a received
wake-up signal TL or to start an activation procedure on the LT-side.
Alerting 1
“Alerting 1” state is entered when a wake-up tone was received in the “Receive Reset”
state and the deactivation procedure on the NT-side was not yet finished. The
transmission of wake-up tone TN is started.
Analog Loop-Back
Upon detection of binary “1s” for a period of 6–12 ms and of the superframe indication,
the “Analog loop-back” state is entered and transparency is achieved in both directions
of transmission. This state can be left by making use of any unconditional command.
Only the C/I-channel code RES should be used, however. This assures that the EC- and
EQ-coefficients are set to zero and that for a subsequent normal activation procedure
the receiver updating algorithms converge correctly.
Deactivated
The ’Deactivated’ state is a power-down state. If there are no pending Monitor channel
messages from the U-transceiver, i.e. all Monitor channel messages have been
Interrupt (Stand-alone mode only)
A level change on input pin INT triggers the transmission of this C/I code in four
successive IOM-2 frames. Please refer to page 96 for details.
Power Up
The U-transceiver provides IOM-2 clocks.
States
a = 0/1 corresponds to ACT-bit set to binary “0/1”
70
U-Transceiver
PSB 21911
PSF 21911
11.97