Motorola V3229 - 14.4 Kbps Modem, Operating Instructions Manual

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V.3229 / V.3229L <C#>-1
6
Status Registers
Chapter 6
Status Registers
S-REGISTERS
Most modem configuration information is stored in
a part of memory called status (S) registers. During
operation this information is used to determine mo-
dem functions.
The information stored in the S-registers is changed
by the AT or V.25b command sets and by pushbut-
tons in response to the LCD prompt. These are the
preferred methods. Some software programs also
access the S-registers via the AT command set, but
this action is transparent to the user.
The ATS
commands indicate which memory bit(s) to alter to
select a particular option or to perform a certain
function. The S-register values comprise the config-
uration profile.
Caution: The purpose of this tutorial is to show the
versatility of option selection and register function.
It is strongly recommended that the preferred meth
-
ods of option selection be used. This tutorial uses
S22 as the example register. Certain modems may
use S22 differently or may not have an S22.
Generally the user should not directly alter S-register
values. However, the user has the option of changing
S-registers via ATS commands and directly altering
the register value. This is called "writing" to the S-
register. Writing to an S-register is not a preferred
method and should only be used by programmers
who need to manipulate S-registers so they can inter-
act with a software program under development or
some other similar action.