Intel 537EX - Manual (Page 88)

88 536EX Chipset Developer’s Manual
Intel Confidential
S-Registers
S21 48
Bit-Mapped Options: S21 is a read-only register that indicates AT command settings.
Bit 0 Reserved
Bit 1 Reserved
Bit 2 Reserved
Bits 4–3 00 &D0 is selected
01 &D1 is selected
10* &D2 is selected
11 &D3 is selected
Bit 5 0 &C0 is selected
1* &C1 is selected
Bit 6 0* &S0 is selected
1 &S1 is selected
Bit 7 0* Y0 is selected
1 Y1 is selected
S22 118
Bit-Mapped Options: S22 is a read-only register that indicates AT command settings.
Bits 1–0 00 L0 is selected
01 L1 is selected
10* L2 is selected
11 L3 is selected
Bits 3–2 00 M0 is selected
01* M1 is selected
10 M2 is selected
11 M3 is selected
Bits 6–4 000 X0 is selected
001 Reserved
010 Reserved
011 Reserved
100 X1 is selected
101 X2 is selected
110 X3 is selected
111* X4 is selected
Bit 7 0* &P0 is selected
1 &P1 is selected
S25 5
Detect DTR Change: S25 defines the minimum amount of time that DTR has to remain off (that
is, on-to-off-to-on transitions) before the modem performs the function specified by &Dn
command. A change in DTR that persists for a shorter time than the value specified in S25 is
ignored by the modem (see the &Dn command).
Range: 0–255 (1/100 of a second)
S30 0
Disconnect Inactivity Timer: This S-register sets the length of time (in minutes) that the
modem stays online/off-hook before disconnecting when no data is being transmitted or
received. In data and fax modes, any data transmitted or received between the DTE-DCE
interface resets the timer. In all other modes (except Telephone-Emulation mode), any data
transmitted resets the timer. In Telephone-Emulation mode, S30 is ignored (that is, the modem
does not automatically hang up the line after a given time delay).
Range: 0–255 minutes
0 Disabled
Table 26. S-Register Command Descriptions (Continued)
Command Default Description
NOTE: An asterisk (*) denotes the factory-default setting.