r6781-12 Conexant Systems, Inc., r6781-12 Datasheet - Page 59

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

EmbeddedModem Family
Table 5-2. S Register Description (3 of 8)
D224ATLVDSC
Register
S16
S17
S18
S19
S20
Default
00
00
00
—
0
Range
0-250
0-255
1-127
—
—
Increments
Seconds
Seconds
Units
None
4 ms
—
Conexant
Modem Test Option. Controls the diagnostic modes as follows:
Fax Mode Null Byte Timer. The value of S17 determines the
length of time null bytes are sent by the modem if the last byte
sent during DTE underrun in Fax Mode is not a null byte.
0
the timer value is the value of S17 times 4 ms).
Test Timer. Sets the length of time the modem conducts a test
before returning to the command mode. If this register is zero, the
test will not automatically terminate; the test must be terminated
from the command mode by issuing an AT&T0 or ATH command.
Not Supported
Fax Mode Inactivity Timer. S20 can be used to cause the modem
to automatically place the telephone on-hook or reset itself if
inactivity (of variable duration) is detected while in Fax Mode.
Bit 0
Bit 1
Bit 2
Bit 3
S17
Local Analog Loopback L3 (See &T1 command)
0
1
Reserved
Local Digital Loopback (See &T3 command)
0
1
Remote Digital Loopback L2 (See &T6 command)
0
1
250 corresponds to a timer value of 0–1 second (i.e.,
Disabled (factory default)
&T1
Disabled (factory default)
&T3
Disabled (factory default)
&T6
—
—
—
Enabled
Enabled
Enabled
Description
5-5