Specifications

AN93
86 Rev. 0.9
3.3.29. U65 (DAAC4)
U65 (DAAC4) is a bit-mapped register with bits 3:0,
12:5, and 15 reserved. Bits 1:0 and 6:5 must not be
changed in a read-modify-write cycle.
Bit 14 (PWMG) = 0 (default) provides 0 dB gain to
AOUT. PWMG = 1 provides a 6 dB gain to AOUT.
Bit 13 (PDN) = 0 allows the device to operate at normal
power level. PDN = 1 completely powers down both the
Si3018/10 and the Si2493/57/34/15/04 chips.
The bit takes effect at the carriage return of the AT
command writing this bit to a 1. Once this bit is set, the
modem must be reset via the RESET
pin (Si2493/57/
34/15/04, pin 12) to become active. When reset, the
modem reverts to the default settings.
Bit 4 (PDL) = 0 (default) allows the modem to operate at
normal power levels. PDL = 1 powers down the Si3018/
103018/10. This is a test mode typically used for board-
level debugging, not normal modem operation.
U65 resets to 0x00E0 with a power-on or manual reset.
3.3.30. U66 (DAA Control Register 5, DAAC5)
U66 (DAAC5) is a bit-mapped register with all bits
except bit 6 reserved (see Table 53).
Bit 6 (FDT) is a read-only bit that reports whether or not
an isolation capacitor frame lock is established. FDT is
typically used for board-level debugging and is not used
during normal modem operation.
U66 resets to 0xXX40 with a power-on or manual reset
assuming framelock is established. The upper byte is
variable.
3.3.31. U67–U6A (International Configuration Regis-
ters)
International Configuration Registers include U67
through U6A. These are bit-mapped registers that
control international configuration settings, such as dc
and ac termination, ringer impedance and detection,
current limit, and billing tone protection.
3.3.32. U67 (ITC1)
U67 is a bit-mapped register with bits 5:4, 8, 11:10, and
15:14 reserved (see Table 54). U67 resets to 0x0008
with a power-on or manual reset.
Bit 7 (DCR) is used to set the dc line termination of the
modem. DCR = 0
b
is the normal mode of operation with
dc impedance selected by U67[3:2] (DCV).
Table 52. U65 Bit Map
Bit Name Function
15 Reserved Read returns zero.
14 PWMG PWM Gain.
0 = No gain.
1 = 6 dB gain applied to AOUT.
13 PDN Powerdown.
0 = Normal.
1 = Powerdown.
12:7 Reserved Read returns zero.
6:5 Reserved Must not change in a read-modify-write.
4PDLPowerdown Line-Side Chip.
0 = Normal operation.
1 = Places the Si3018/10 in powerdown mode.
3:2 Reserved Read returns zero.
1:0 Reserved Must not change in a read-modify-write.