Z02215
Single Chip Modem with Integrated Controller, Data Pump, and AFE
37
Modem S-Registers
Modem S-registers contain the values of special purpose ASCII characters, timing
parameters and other modem parameters. The value of an S-register is modified
by the AT S command. Each S-register has three values that may be configured
for specified countries: a default value, an upper limit, and a lower limit. The val-
ues described in this manual are for North America.
Table 7. Modem S-Registers
Register Range
Default Units
Description
S0
0–255
0
Rings
Sets number of rings before auto-answer. The modem
automatically answers the telephone after it rings the number
of times specified in register S0. If S-register S0 is 0 the
modem does not automatically answer the telephone. Any
value from 0 to 255 is valid. The country configuration may
disable the modem’s ability to detect a telephone line ring
signal. In this case, the modem never automatically answers
the telephone regardless of the S0 setting. The default value
is 0 (auto-answer disabled)
S1
S2
S3
0–255
0–255
0–127
0
Rings
ASCII
ASCII
Returns the number of times the phone rings. When the
modem is in the IDLE state and set to automatically answer
the telephone (S-register S0 > 0), the modem records the
number of times the phone rings in S-register S1. The value of
S1 reverts to 0 if no ring occurs for several seconds.
43
13
Sets escape sequence character. S-register S2 is the value
of the escape sequence character. Setting S2 to a value
greater than 127 disables the character escape sequence,
preventing the modem from returning to Command state when
in the ON-LINE state. The ASCII default value is +.
Sets the end-of-line character. S-register S3 is the value of
the end of line character. S3 is used at the end of command
lines and result codes.
S4
S5
0–127
0–127
10
8
ASCII
ASCII
Sets the line feed character. S-register S4 is the value of the
character for line feed.
Sets the backspace character. S-register S5 is the value of
the character for backspace. This character moves the cursor
left on a command line, deleting the previous character.
PS001907-0904
Modem S-Registers
ZILOG [ ZILOG, INC. ]
