Silicon Laboratories SI2493/57/34/15/04 - Manual (Page 134)

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134 Rev. 1.3
6.2.2. Country Configuration
The modem default settings are for the US-like countries. Many countries use at least some of the default register
settings. Default values do not have to be written when configuring the modem to operate in a particular country,
assuming the modem was reset just prior to the configuration process. To avoid confusion and possible errors,
the modem should be reset prior to reconfiguration between countries.
Some countries have unusual requirements. For example, registers U37–U40 set the number of pulses to dial
digits 0 through 9, respectively. By default, digit 1 has a setting of 1 pulse; digit 2 has a setting of 2 pulses, and so
on. Digit 0 has a setting of 0xA (10 decimal) pulses. This pulse arrangement is used nearly universally throughout
the world. However, New Zealand requires ten pulses for 0, nine pulses for 1, eight pulses for 2, and so on.
Sweden, on the other hand, requires one pulse for 0, two pulses for 1, and so on.
Japan requires both the usual 10 pps pulse dialing and 20 pps pulse dialing. To configure the modem for 20 pps,
set U42 (PDBT) = 0x0022, U43 (PDMT) = 0x0010, and U45 (PDIT) = 0x0258. The %P command may also be
used.
The Netherlands has a unique dial-tone filter. Other countries, such as Japan, have special low-voltage loop
requirements. South Korea, Poland, and South Africa have special ringer impedance requirements. Set all country-
specific parameters listed in Table 90.
In order to use the +GCI command for a given country and modify one or more U registers, it is necessary to
execute the +GCI command first, then modify the desired register or registers. The +GCI command resets all U
registers through U86 and S7 to factory defaults before applying the country-specific settings. A compliance
laboratory can verify whether the countries that accept the legacy TBR21 specification still accept their previous
settings. It is advantageous in terms of heat dissipation to disable the TBR21 current limit. In order to disable loop-
current limiting, bit ILIM (U67 [9]) should be set to zero after the +GCI command.
Table 90 contains recommended updates to the +GCI register settings. The U-register writes must be loaded after
the +GCI command. Some TBR21 and ES 203 021 countries require blacklisting. This can be enabled with
S42 = 1. Some also require a minimum period of time between calls that can be set with S50 = 6.
6.2.2.1. Country Initialization Table
Table 90. Country Initialization Table
Country Initialization
Algeria*
AT+GCI=2E
AT:U35,10E0
AT:U46,9B0
AT:U62,904
Argentina*
AT+GCI=51
AT:U46,680
AT:U52,1
ATS007=50
Armenia*
AT+GCI=73
ATS007=80
Australia
AT+GCI=9
AT:U42,55,F
AT:U4F,79
AT:U52,2
ATS006=3
*Note: These countries do not have a built-in +GCI support but are
using the settings of other countries as a shortcut.