Z02205 Datasheet, PDF (21/30 Pages) Zilog, Inc. – MODEM CONTROLLER IDEAL FOR LOW POWER CONSUMPTION, SMALL SIZE REQUIREMENTS

ZiLOG
Register
S21
S22
S23
S24
S25
Range
Reserved
Reserved
Reserved
Reserved
0–255
S26
Reserved
S27
Reserved
S28
0–255
S29
0–255
S37
0–6
Z02205
Modem Controller
Table 4. Modem S-Registers (Continued)
Units
Description
Reserved Reserved
Reserved Reserved
Reserved Reserved
Reserved Reserved
seconds
During synchronous operation with the &Q1 command in effect, S-register S25 indicates
or 1/100 sec. the number of seconds after a telephone line connection is made before the modem
examines DTR. This register allows sufficient time to disconnect the modem from an
asynchronous terminal and attach it to a synchronous terminal. In the On-Line or
Command state during any mode of operation, changes in DTR for less than S25
hundredths of a second are ignored.
Reserved Reserved
Reserved Reserved
minutes
Terminal inactivity timeout. Hangs up the modem after S28 minutes if no characters are
received from the modem’s terminal. Default = 0
1/50th sec
code
Hook Flash On-Hook time. The amount of time in 20 millisecond units the modem will
leave the telephone on-hook while performing a hook-flash according to the “!” dial
string modifier. Default = 25 fiftieths of a second.
Sets the Highest Line Rate. This register determines the highest telephone line data rate
the modem will use when connecting with a remote modem. See “Setting the Highest
Line Rate” section on the following page. Default = 0.
PS001000-MOD0599
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