CMX644A Просмотр технического описания (PDF) - CML Microsystems Plc
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CMX644A Datasheet PDF : 34 Pages
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V22 and Bell 212A Modem
CMX644A
TX TONES Register ($E1)
This register is used to transmit both DTMF and modem progress tones.
TONESEL
(Bit 7)
This bit selects the “Answer Tone” frequency in the receive detector. A
‘0’ selects 2225Hz and a ‘1’ selects 2100Hz.
TONE/NOTONE
(Bit 6)
This bit should be used to begin and end the transmission of tones once
the required frequency has been programmed. When set to ‘1’ the tone
will be transmitted; when set to ‘0’ a Notone (Bias Voltage) will be
generated.
DTMF/MODEM TONES
(Bit 5)
When this bit is set to ‘1’ the device is configured for DTMF. When it is
set to ‘0’ the device is configured to transmit modem progress tones.
DTMF/SNGL
(Bit 4)
For normal DTMF operation this bit should be set to ‘0’. For test
purposes it can be set to ‘1’ in order to select the tone frequencies
individually.
The following table shows the settings required for transmitting DTMF (Bit 5 should be set to ‘1’. Bits 6 and 7
should be operated as described above).
Lower Freq. (Hz) Upper Freq. (Hz) Keypad Single Tone Freq.
D3 D2 D1 D0 (setting Bit 4 = 0) (setting Bit 4 = 0) symbol
(Hz)
(setting Bit 4 = 1)
0000
941
1633
D
1633
0001
697
1209
1
1209
0010
697
1336
2
1336
0011
697
1477
3
1477
0100
770
1209
4
1209
0101
770
1336
5
1336
0110
770
1477
6
1477
0111
852
1209
7
1209
1000
852
1336
8
852
1001
852
1477
9
852
1010
941
1336
0
941
1011
941
1209
*
941
1100
941
1477
#
941
1101
697
1633
A
697
1110
770
1633
B
770
1111
852
1633
C
852
The following table shows the settings required for transmitting modem progress tones. (Set Bit 4 to ‘0’ and
Bit 5 to ‘0’. Bits 6 and 7 should be operated as described earlier).
D3 D2 D1 D0 Frequency (Hz)
0000
0001
0010
0011
0100
550
1300
1800
2100
2225
Tone
Description
Guard
Calling
Guard
Answer
Answer
© 2000 Consumer Microcircuits Limited
12
D/644A/6
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