
Si2400
Rev. 1.3
17
5.3. Low Power Modes
The Si2400 has three low power modes. These are
described below:
DSP Powerdown. The DSP processor can be
powered down by setting register
SEB[3] (PDDE) = 1b.
In this mode, the serial interface still functions and
the modem will detect ringing and intrusion.
However, no modem modes or tone detection
features will function.
Wake-Up-On-Ring. By issuing the ATz command,
the Si2400 goes into a low power mode where both
the microcontroller and DSP are powered down.
Only an incoming ring or a total reset will power up
the chip again. Return from wake-on-ring will trigger
the ALERT pin if S62[4] (WOR) = 1b (WOR = 0b by
default).
Total Powerdown. Setting SF1[5] = 1b and
SF1[6] = 1b will place the Si2400 into a total
powerdown mode. All logic is powered down,
including the crystal oscillator and clock-out pin.
Only a hardware reset can restart the Si2400.
5.4. Global DAA Operation
The Si2400 chipset contains an integrated silicon direct
access arrangement (silicon DAA) that provides a
programmable line interface to meet international
telephone line requirements.
Table 13 gives the DAA
register settings required to meet various country PTT
standards. A detailed description of the registers in
Table 13. Country-Specific Register Settings
Register
SF5
SF7
SF6
S62
Country
OHS
ACT
DCT
RZ
RT
LIM
VOL
FLVM
LLC
Australia1
11
01
00
0
Brazil2
00
01
00
0
CTR211, 3, 4
01
10
00
1
0
1
Czech Republic
0
1
10
0
FCC1, 5
00
10
00
0
Latvia
01
11
00
1
0
Malaysia1,6
00
01
00
0
New Zealand
0
1
10
0
Nigeria
0
1
11
0
1
0
Philippines1
00
01
00
0
1
0
Poland7, Slovenia
0
10
1
0
South Africa7
10
0
South Korea7
00
01
10
0
Note:
2. The following countries require the same settings as Brazil: Armenia, China, Egypt, Georgia, Japan, Jordan,
Kazakhstan, Kyrgyzstan, Malaysia, Muldova, Oman, Pakistan, Qatar, Russia, Syria, Taiwan, Thailand, Ukraine.
3. The following countries require the same settings as CTR21: Austria, Bahrain, Belgium, Bulgaria, Croatia, Cyprus,
Denmark, Estonia, European Union, Finland, France, Germany, Greece, Guadeloupe, Iceland, Ireland, Israel, Italy,
Lebanon, Liechtenstein, Luxembourg, Malta, Martinique, Morocco, Netherlands, Norway, Polynesia (French),
Portugal, Reunion, Spain, Sweden, Switzerland, Turkey, and the United Kingdom.
4. When changing into or out of CTR21 Mode, LLC should be written first. SDF must be enabled (i.e., DGSR
≠ 0) and
SFS should be reprogrammed before each call.
5. The following countries require the same settings as FCC: Argentina, Brunei, Canada, Chile, Columbia, Dubai,
Equador, El Salvador, Guam, Hong Kong, Hungary, India, Indonesia, Kuwait, Macao, Mexico, Peru, Puerto Rico,
Romania, Saudi Arabia, Singapore, Slovakia, Tunisia, UAE, USA, Venezuela, Yemen.
6. Supported for loop current
≥ 20 mA.
7. SF5[1] (RZ) should only be set for Poland, South Africa and South Korea if the ringer impedance network (C15, R14,
Z2, Z3) is not populated.