CMX878D6 View Datasheet(PDF) - CML Microsystems Plc
Part Name
Description
MFG CO.
'CMX878D6' PDF : 63 Pages View PDF
Line Powered Modem plus DAA
CMX878
1.5.12.9 Transmit Mode Register
Transmit Mode Register: 16-bit write-only. C-BUS address $E1
This register controls the CMX878 transmit signal type and level. All bits of this register are cleared to 0
by a General Reset command or when b7 (Reset) of the General Control Register is 1.
Bit: 15 14 13 12
Tx mode = modem
Tx mode = DTMF/Tones
Tx mode = Disabled
11 10 9
Tx level
Tx level
8
7
Guard tone
6
5
Scrambler
Unused, set to 0000
Set to 0000 0000 0000
4
3
2
1
0
Start-stop /
# data bits /
synch data synch data source
DTMF or Tone select
Tx Mode Register b15-12: Tx mode
These 4 bits select the transmit operating mode.
b15 b14 b13 b12
1 1 1 1 V.22bis 2400 bps QAM
1110
“
1 1 0 1 V.22/Bell 212A 1200 bps DPSK
1100
“
1 0 1 1 V.22 600 bps DPSK
1010
“
1 0 0 1 V.21 300 bps FSK
1000
“
0 1 1 1 Bell 103 300 bps FSK
0110
“
0 1 0 1 V.23 FSK
0100
“
0 0 1 1 Bell 202 FSK
0010
“
0 0 0 1 DTMF / Tones
0 0 0 0 Transmitter disabled
High band (Answering modem)
Low band (Calling modem)
High band (Answering modem)
Low band (Calling modem)
High band (Answering modem)
Low band (Calling modem)
High band (Answering modem)
Low band (Calling modem)
High band (Answering modem)
Low band (Calling modem)
1200 bps
75 bps
1200 bps
150 bps
Tx Mode Register b11-9: Tx level
These 3 bits set the gain of the Tx Level Control block.
b11 b10 b9
1
1
1
0dB
1
1
0 -1.5dB
1
0
1 -3.0dB
1
0
0 -4.5dB
0
1
1 -6.0dB
0
1
0 -7.5dB
0
0
1 -9.0dB
0
0
0 -10.5dB
© 2002 Consumer Microcircuits Limited
35
D/878/2
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