Specifications

AN93
96 Rev. 0.9
3.3.46. U7D (GEND)
U7D is a bit-mapped register with bits 15,13:9, and bits
8:2 reserved. U7D resets to 0x0000 with a power-on or
manual reset.
Bit 14 (NLM) = 0 (default) causes the modem to
automatically detect loop current absence or loss. When
bit 14 = 1b, this feature is disabled.
Bit 12 (TCAL) = 0 (default) when set to 1 forces the DAA
to calibrate at a programmable time after going off-hook.
The time between going off-hook and the start of
calibration is programmed with U54[15:8] in 32 ms
units.
Bit 11 (OHCT) = 0 (default) when set to 1 forces the
DAA to calibrate at the start of dialing. The first dial
character should be a delay (“,”) to prevent interference
with the first digit.
Bit 1 (ATZD) = 0 (default) allows the ATZ command to
be active. When Bit 1 = 1b, the ATZ command is
disabled.
Bit 0 (FDP) = 0 (default). FSK data processing stops
when the carrier is lost. Unprocessed data is lost.
Setting Bit 0 = 1 causes FSK data processing to
continue for up to two bytes of data in the pipeline after
carrier is lost.
Table 67. U7C Bit Map
Bit Name Function
15:5 Reserved Read returns zero.
4RIGPORI (Si2493/57/34/15/04 pin 15).
Follow this bit when U7C[0] (RIGPIOEN) = 1
b
.
3:1 Reserved Read returns zero.
0 RIGPOEN 0 = RI (Si2493/57/34/15/04 pin 15) indicates valid ring signal.
1 = RI (Si2493/57/34/15/04 Pin 15) follows U7C[4] (RIGPO).
Table 68. U7D Bit Map
Bit Name Function
15 Reserved Read returns zero.
14 NLM 0 = Enables “No Loop Current” Detect.
1 = Disables “No Loop Current” Detect.
13 Reserved Read returns zero.
12 TCAL 0 = Timed calibration disabled.
1 = Timed calibration. The time between off-hook and calibration is set in U54 (OHCT).
11 CALD 0 = No calibration during dial.
1 = Calibrate during dial. It is recommended that the dial string start with “,” to prevent first
digit loss.
10:2 Reserved Read returns zero.
1 ATZD 0 = ATZ enabled.
1 = ATZ disabled.
0FDP0 = FSK data processing stops when carrier is lost.
1 = FSK data processing continues for two bytes after carrier is lost.