psf21911 ETC-unknow, psf21911 Datasheet - Page 73

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

Synchronized 1
When reaching this state the U-transceiver informs the LT-side by sending the
superframe indication (inverted synch.-word). The loop-back commands decoded by the
EOC-processor control the output of the transmit signals:
– Normal ACT and UOA = 0:
– Any loop-back and UOA = 0 (no loop-back):
The value of the issued SAI-bit depends on the received C/I-channel code: DI and TIM
lead to SAI = 0, any other C/I-code sets the SAI-bit to 1 indicating activity on the S/T-
interface. The U-transceiver waits for the receipt of UOA = 1 to enter the “Synchronized
2” state.
Synchronized 2
In this state the U-transceiver has received UOA = 1. This is a request to activate the
S/T-reference point. The loop-back commands detected by the EOC-processor control
the output of indications and transmit signals:
– Normal activation and UOA = (1):
– Single channel loop-back and UOA = (1):
– Loop-back 2 (LBBD):
The value of the issued SAI-bit depends on the received C/I-channel code: DI and TIM
lead to SAI = 0, any other C/I-code sets the SAI-bit to 1 indicating activity on the S/T-
interface. The U-transceiver waits for the receipt of the C/I-channel code AI to enter the
“Wait for ACT” state.
Test
The “Test” mode is entered when the unconditional commands RES, SSP, Pin-RES or
Pin-SSP are used. It is left when normal U-transceiver operation is selected via pins RES
and TSP and the C/I-channel codes DI or ARL are received.
The following signals are transmitted on the U-interface:
– No signal level (SN0) when the C/I-channel code RES is applied or a hardware reset
– Single pulses (SP) when the C/I-channel code SSP is applied or pin TSP =1.
Transparent
This state is entered upon the detection of ACT = 1 received from the LT-side and
corresponds to the fully active state. In the case of a normal activation in both directions
of transmission the the following codes are output:
– Normal activation or single-channel loop-back:
– Loop-back 2:
Semiconductor Group
is activated.
73
SN3 and AR
SN3
SN3T
SN3T and AR
SN3T and ARL
AI
AIL
U-Transceiver
PSB 21911
PSF 21911
11.97