CMX865 CML Microcircuits, CMX865 Datasheet - Page 20

• Manufacturer Part Number: CMX865
• Description: FSK Modem and DTMF Codec
• Manufacturer: CML Microcircuits

FSK Modem and DTMF Codec
5.10.3 Transmit Mode Register
Transmit Mode Register: 16-bit write-only.
This register controls the CMX865 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.
© 2005 CML Microsystems Plc
Bit:
Tx Mode Register b15: Reserved, set to 0
Tx Mode Register b14-12: Tx Mode
These three bits select the transmit operating mode.
Tx Mode Register b11-9: Tx Level
These three bits set the gain of the Tx Level Control block.
Tx Mode Register b8: Reserved, set to 0
b14
15
b11
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
14
b13
DTMF/Tones
1
1
0
0
1
1
0
0
Tx mode =
Tx mode =
Tx mode =
b10
Disabled
modem
1
1
0
0
1
1
0
0
13
b12
1
0
1
0
1
0
1
0
12
b9
1
0
1
0
1
0
1
0
Bell 103 300bps FSK
“
V.23 FSK
“
Bell 202 FSK
“
DTMF / Tones
Transmitter disabled
11
-1.5dB
-3.0dB
-4.5dB
-6.0dB
-7.5dB
-9.0dB
-10.5dB
0dB
Tx level
Tx level
10
9
C-BUS address $E1
8
0
0
Set to 0000 0000 0000
20
7
0
DTMF Twist
6
0
5
0
High band (Answering modem)
Low band (Calling modem)
75bps
1200bps
150bps
1200bps
Start-stop /
synch data
4
DTMF or Tone select
3
synch data source
2
# data bits /
1
0
CMX865
D/865/3