SI2414 SILABS [Silicon Laboratories], SI2414 Datasheet - Page 71

• Manufacturer Part Number: SI2414
• Manufacturer: SILABS [Silicon Laboratories]

Si2456/Si2433/Si2414
runs the ITU V.54 loopback test 3 via the hybrid path in
the DAA. After a connection is complete, the
ISOmodem issues the “CONNECT xxx” response, and
data is passed from the TXD pin, out the loop, and back
to the RXD pin. This loopback test is a very complete
line test. If desired, further testing is possible by
connecting the ISOmodem to a dummy phone line and
running any variety of functional tests.
A test of the ISOcap link only may be initiated by setting
the DL bit (U62, bit 1) = 1 and issuing the AT&T3
command. This test implements the ITU V.54 loopback
test 3 but eliminates the hybrid from the path. Finally, a
digital-only loopback that does not involve the line-side
device (Si3015) may be initiated via the AT&T2
command. This test is also the ITU V.54 loopback test 3.
The billing tone filter affects the ac termination and
return loss. The current complex ac termination passes
worldwide return loss specifications with and without the
billing tone filter by at least 3 dB. The ac termination is
optimized
for
frequency
response
and
hybrid
cancellation while having greater than 4 dB of margin
with or without the dongle for South African, Australian,
CTR21,
German,
and
Swiss
country-specific
specifications.
Rev. 0.9
71