AN93

The even-numbered registers, (UA0, UA2, etc.), control the amount of time the tone is expected to be present, and the odd-numbered registers select the amount of time the tone must not be present. The values are expressed in 10 millisecond units. For example, a cadence of on 500 ms, off 300 ms then on for 500 ms may be selected by writing 0x0032 to UA0, 0x001E to UA1 and 0x0032 to UA2. The unused registers should be written to 0. The default cadence setting is UA0 equal to 001Eh, and the remaining nine registers are set to zero.

Table 101 defines the SAS cadence for each supported country. The on-time is listed in bold. These data were obtained from ITU-T Recommendation E.180 Supplement 2 (04/98).

Table 100. SAS Tone Frequency

SAS_FREQ (U9F)

SAS Frequency

0x0000

440 Hz (Default)

0x0001

400 Hz

0x0002

420 Hz

0x0003

425 Hz

0x0004

480 Hz

0x0005

450 Hz

0x0006

900 Hz

0x0007

950 Hz

0x0008

523 Hz

0x0009

1400 Hz

Table 101. SAS Cadence for Supported Countries*

Country

Tone

Frequency (Hz)

Cadence (seconds)

U Registers

 

 

 

 

 

Angola

 

 

1.0 – 5.0

U9F = 0x0001

Waiting Tone

400

UA0 = 0x0064

 

 

 

 

UA1 = 0x01F4

 

 

 

 

 

 

 

 

 

U9F = 0x0000

Anguilla

Waiting Tone

440

0.5 – 10.0 – 0.5

UA0 = 0x0032

UA1 = 0x03E8

 

 

 

 

 

 

 

 

UA2 = 0x0032

 

 

 

 

 

Antigua and

Call Waiting

 

0.6 – 10.0

U9F = 0x0004

480

UA0 = 0x003C

Barbuda

Tone

 

 

UA1 = 0x03E8

 

 

 

 

 

 

 

 

 

 

 

 

 

U9F = 0x0003

Argentine Republic

 

 

0.4 – 0.2 – 0.4 – 4.0

UA0 = 0x0028

Waiting Tone

425

UA1 = 0x0014

 

 

 

 

UA2 = 0x0028

 

 

 

 

UA3 = 0x0190

 

 

 

 

 

152

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Silicon Laboratories SI2493/57/34/15/04, SI2494/39 manual SAS Tone Frequency, SAS Cadence for Supported Countries