SI2493-D-FS Silicon Laboratories Inc, SI2493-D-FS Datasheet - Page 126

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

Specifications of SI2493-D-FS

• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

AN93
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 are 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.
Synchronous access mode <EM> shielding is designed to support XON/XOFF 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 are 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 one <0x99> character needs to be sent as payload,
the host software sends <EM><0x76> instead. For a complete list <EM> commands and statuses, see Table 86.
126
Table 85. Synchronous Access Mode 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
Rev. 1.3
Required to disable MNP,V.42
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.