International DAA parameters
Franc Zabkar
Digital Access Arrangement), I came upon a table which may give an
insight into the different DAA requirements of various countries.
I guess this data may help one decide whether a modem designed for one
particular country would work in another. For example, even though one
may not understand the meanings of the various parameters (and that
includes me), I suspect that merely knowing that two countries fall
within the FCC or CTR21 groups may be a sufficient indicator of
telephone system compatibility. However, the data does not reflect the
differences in busy tones, dialtones, ring cadence, etc. These
functions appear to be left to the DSP.
BTW, there appear to be two flavours of DAA from Silicon Labs. One is
an international version (Si3034) consisting of a line side chip
(Si3014) and a DSP side chip (Si3021). The North American chipset is
designated as Si3035.
Table 16. Country Specific Register Settings
Country OHS ACT DCT RT LIM VOL
Australia 1 1 10 0 00 00
Bulgaria 0 0/1 10 0 00 00
CTR21 0 0/1 11 0 11 00
Czech Rep 0 1 10 0 00 00
FCC 0 0 10 0 00 00
Hungary 0 0 10 0 00 00
Japan 0 0 01 0 00 00
New Zealand 0 1 10 0 00 00
Philippines 0 0 01 0 00 01
Poland 0 0 10 1 00 00
Singapore 0 0 01 0 00 00
Slovakia 0 0/1 10 0 00 00
Slovenia 0 1 10 0 00 00
Sth Africa 1 1 10 0 00 00
South Korea 0 0 01 0 00 00
Notes:
1. CTR21 includes the following countries:
Austria, Belgium, Cyprus, Denmark, Finland, France, Germany, Greece,
Iceland, Ireland, Israel, Italy, Liechtenstein, Luxembourg,
Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, and the
United Kingdom.
2. FCC includes the following countries:
Carribean, Central America, China, Hong Kong, Maylasia, Mexico, Saudi
Arabia, South America, Taiwan, Thailand, United Arab Emirates, and the
United States.
OHS = On-Hook Speed.
1 = The Si3034 will execute a slow, controlled on-hook.
0 = The Si3034 will execute a fast on-hook.
ACT = AC Termination Select.
1 = Selects the complex impedance.
0 = Selects the real impedance.
DCT = DC Termination Select.
00 = Reserved.
01 = Japan Mode. Low voltage mode. (Transmit level = –3 dBm).
10 = USA Mode. Standard voltage mode. (Transmit level = –1 dBm).
11 = CTR21 Mode. Current limiting mode. (Transmit level = –1 dBm).
RT = Ringer Threshold Select.
Used to satisfy country requirements on ring detection. Signals below
the lower level will not generate a ring detection; signals above the
upper level are guaranteed to generate a ring detection.
1 = 17 to 29 Vrms
0 = 11 to 22 Vrms
LIM = Current Limit
11 = CTR21 mode.
00 = All other modes.
VOL = Line Voltage Adjust.
When set, this bit will adjust the tip-ring line voltage. Lowering
this voltage will improve margin in low voltage countries. Raising
this voltage may improve distortion performance.
11 = +0.125V
10 = +0.25V
01 = -0.125V
00 = normal.
-- Franc Zabkar
Please remove one 'e' from my address when replying by email.