r6781-12 Conexant Systems, Inc., r6781-12 Datasheet - Page 60

• Manufacturer Part Number: r6781-12
• Description: Embedded Modem Family
• Manufacturer: Conexant Systems, Inc.

Table 5-2. S Register Description (4 of 8)
5-6
Register
S21
Default
00
Bit Mapped
Range
Units
—
Conexant
Bit Mapped Options. S21 is the modem register with the following
bit functions:
Bit 0
Bit 1
Bit 2
Bit 3, 4 Data Terminal Ready (DTR) (See &D Command)
Bit 5
Bit 6
Bit 7
Telco Jack (See &J Command)
0
1
Reserved
Ready to Send (RTS)/Clear to Send (CTS). (See &R
Command)
0
1
4 3
0 0
0 1
1 0
1 1
Data Carrier Detect (DCD) (See &C Command)
0
1
Data Set Ready (DSR) (See &S Command)
0
1
Long Space Disconnect (See Y Command)
0
1
&J0
&J1
&R0
&R1
&D0
&D1
ON-to-OFF transition on DTR
&D2–Modem “hangs up” if ON-to-OFF
transition on DTR
&D3
ON-to-OFF transition on DTR
&C0
&C1
presence of a valid data carrier
&S0
&S1
handshaking
&Y0
&Y1
—
—
—
—
—
—
—
—
—
—
—
—
—
11/RJ-45S (factory default)
RJ-12/RJ-13
DCD is always on (factory default)
An ON condition on DCD indicates the
DSR is always on
DSR is turned on at the start of
Disabled (factory default)
Enabled
CTS tracks RTS (not supported)
RTS is ignored (factory default)
Modem ignores DTR (factory default)
Modem goes to command state if
Modem goes to initialization state if
Description
EmbeddedModem Family
D224ATLVDSC