Low Power V.32 bis Modem
CMX869
6.4
Receive Mode Register
Receive Mode Register: 16-bit write-only.
C-BUS address $E2
This register controls the CMX869 receive 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.
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Bit:
Rx mode = modem
Rx level
000
Start-stop/Synch
No. of bits and
parity
Rx mode = Tones detect
Rx mode = Disabled
Rx level
DTMF/Tones/Call Progress select
Set to 0000 0000 0000
Rx Mode Register b15-12: Rx mode
These 4 bits select the receive operating mode.
b15 b14 b13 b12
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
0
0
0
1
1
1
1
0
0
0
0
1
0
0
1
0
0
1
1
0
0
1
1
0
0
x
1
0
x
Reserved, do not use
Reserved, do not use
V.22, V.22 bis, V.32, V.32 bis
Reserved, do not use
QAM modem
1
0
1
0
1
0
1
0
1
0
V.21 300 bps FSK
High band (Calling modem)
Low band (Answering modem)
High band (Calling modem)
Low band (Answering modem)
1200 bps
75 bps
1200 bps
150 bps
“
Bell 103 300 bps FSK
“
V.23 FSK
“
Bell 202 FSK
“
DTMF, Programmed tone pair, Answer Tone, Call Progress detect
Receiver disabled
Rx Mode Register b11-9: Rx level
These three bits set the internal gain of the Rx Gain Control block.
b11
b10
b9
1
1
1
1
0
0
0
0
1
1
0
0
1
1
0
0
1
0
1
0
1
0
1
0
0dB
-1.5dB
-3.0dB
-4.5dB
-6.0dB
-7.5dB
-9.0dB
-10.5dB
© 2004 CML Microsystems Plc
25
D/869/4
CMLMICRO [ CML MICROCIRCUITS ]
