Silicon Laboratories SI2493/57/34/15/04 - Manual (Page 79)

AN93
Rev. 1.3 79
Figure 25. Phone Line Termination Circuit
&X1
Automatic determination of telephone line type.
Result code: WXYZn
W:
0 = line supports DTMF dialing.
1 = line is pulse dial only.
X: 0 = line supports 20 pps dialing.
1 = line supports 10 pps dialing only.
Y: 0 = extension network present (PBX).
1 = outside line (PSTN) connected directly.
Z: 0 = continuous dial tone.
1 = make-break dial tone.
n: 0–9 (number required for outside line if Y = 0).
1
&X2 Same as &X1, but Y result (PBX) is not tested.
Y2A
2
Produce a constant answer tone (ITU-T) and return to command mode. The answer tone continues
until the ATH command is received or the S7 timer expires.
&Z Enter low-power wake-on-ring mode.
Table 40. Extended AT& Command Set (Continued)
Notes:
1. The initial number attempted to test for an outside line is controlled by S51 (default = 1).
2. AT&$ reflects the last AT&P command issued but does not reflect any subsequent changes made by writing U registers
with AT:U.
RING
Si3018 V
TR
I
L
600

10 µF
+
–
TIP