SI2493-C-FS Silicon Laboratories Inc, SI2493-C-FS Datasheet - Page 24

• Manufacturer Part Number: SI2493-C-FS
• Description: IC ISOMODEM SYSTEM-SIDE 16SOIC
• Manufacturer: Silicon Laboratories Inc

Specifications of SI2493-C-FS

• 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: UART
• Voltage - Supply: 3 V ~ 3.6 V
• Mounting Type: Surface Mount
• Package / Case: 16-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

AN93
the Framed Submode can be used in the same
applications currently using the Legacy Synchronous
DCE Mode.
Prior to sending the ATDT to establish a synchronous
access mode connection, the following commands and
registers require initialization: +MS, +ES, +ESA, +ITF,
+IFC, U87, and U7A.
As an example, the closest equivalent to the Legacy
Synchronous DCE Mode is the following initialization
setting.
With either Synchronous Access Submode, once a
connection has been established, payload data is
multiplexed with command/indicator information by use
of <EM> shielding. With <EM> shielding, either of the
two bytes <0x19> or <0x99> (used to represent <EM>)
precedes a special command or special indicator.
Note that the synchronous access mode <EM>
shielding
handshaking. As such, the bytes 0x13 and 0x11 (XON/
XOFF) are considered to be special characters in the
same way the 0x19 and 0x99 bytes, used for <EM>, are
special.
Since the payload data is multiplexed with <EM>
shielded command/indicator and possibly XON/XOFF
characters, Transparency <EM> codes are defined for
the purpose of allowing the host software to send 0x13,
0x11, 0x19 and 0x99 bytes to/from the DCE. For
example, if the desire is to send one <0x99> character
as a payload character, the host software sends
<EM><0x76> instead. For a complete list <EM>
commands and statuses, see Table 13.
24
is
designed
to
support
XON/XOFF
Rev. 0.9
In addition, a common Point-of-Sale V.22 Fast Connect
Handshake Protocol (with transparent HDLC) requires
these additional settings:
AT\N0
AT+ES = 6,,8
AT+ESA = 0,0,0,,1,0
AT+IFC = 2,2
AT+ITF = 0383,0128
AT:U87,050A
Table 11. Synchronous Access Mode Settings
AT:U7A,3
AT+MS = V22
Table 12. Fast Connect Settings
Set Fast Connect, Transmit
HDLC Flags instead of Marks
during handshake negotiation.
Required to disable MNP,V42
and other protocols
Enable synchronous access
mode on originate or answer
Send Abort on underrun/over-
run in Framed Submode.
Enable CRC generation and
checking.
CTS/RTS Flow Control
Controls CTS Flow Control
Threshold. CTS off at 383
bytes, CTS On at 128 bytes.
Direct to Framed Sub-mode
upon connection. DCE starts
to transmit upon receipt of 10
bytes from the DTE.
V22 Protocol