SI2493-C-FT Silicon Laboratories Inc, SI2493-C-FT Datasheet - Page 132

• Manufacturer Part Number: SI2493-C-FT
• Description: 56 KBPS, V.92 ISOMODEM SYSTEM-SIDE - LEAD-FREE TSSOP 0 TO 7
• Manufacturer: Silicon Laboratories Inc

Specifications of SI2493-C-FT

• Mfg Application Notes: SI2493/57/34/15/04, Appl Note AN93
• Data Format: V.21, V.22, V.23, V.29, V.32, V.34, V.90, V.92, Bell 103, Bell 212A
• Baud Rates: 56k
• Interface: Parallel
• Voltage - Supply: 3 V ~ 3.6 V
• Mounting Type: Surface Mount
• Package / Case: 24-TSSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

AN93
3.5.17.2. Receiving Modem-On-Hold Requests
If Modem-on-hold is enabled via the +PMH=1
command, the Si2493 may be placed on hold by a
remote modem. The maximum time the modem will
remain on hold is configured with the +PMHT setting.
Possible values of +PMHT are given in Table 88. Upon
receipt of a Modem-on-hold request, the Si2493 will
indicate +PMHR: followed by the code corresponding to
the timeout granted. The DCD pin will de-assert while
the modem is on hold, and the CONNECT result code
will indicate a return to data mode. A modem disconnect
due to a timeout or failed negotiation will result in a NO
CARRIER result code.
3.5.18. V.92 Quick Connect
The Si2493 supports ITU-T V.92 shortened Phase 1
and Phase 2 to decrease the time required to connect to
a server modem using the V.90 modulation. After the
first call, the Si2493 will retain line parameters that allow
it to use shortened Phase 1 and 2 to reduce the total
negotiation time. If line conditions change or the remote
server does not support the shortening of these phases,
the modem will automatically connect with the normal
Phase 1 and Phase 2 negotiation unless specifically
commanded not to. Two AT commands control this
feature: AT+PQC and AT+PSS.
The AT+PQC command controls the enabling and
disabling of shortened Phase 1 and Phase 2 individually
according to Table 89. It is recommended that both
shortened phases be used to realize the maximum
reduction in connect time. The possible settings of the
AT+PSS command are shown in Table 90. The AT+PSS
command may be used to force quick connect by
setting AT+PSS = 1; however, this is not recommended
because calling a server that does not support this
feature will result in a failed connection.
132
Rev. 0.9
<Value>
<Value>
10
12
13
11
0
1
2
3
0
1
2
3
4
5
6
7
8
9
Table 88. Possible +PMHT Settings
Table 89. AT+PQC Parameters
Deny V.92 Modem-on-Hold Request
Grant MOH with 10 second timeout
Grant MOH with 20 second timeout
Grant MOH with 30 second timeout
Grant MOH with 40 second timeout
Grant MOH with 1 minute timeout
Grant MOH with 2 minute timeout
Grant MOH with 3 minute timeout
Grant MOH with 4 minute timeout
Grant MOH with 6 minute timeout
Grant MOH with 8 minute timeout
Grant MOH with 12 minute timeout
Grant MOH with 16 minute timeout
Grant MOH with indefinite timeout
Enable Short Phase 1 and Short Phase 2
Enable Short Phase 1
Enable Short Phase 2
Disable Short Phase 1 and Short Phase 2
Description
Description