Marine VHF Audio and Signalling Processor
CMX885
device to cease all processing activity, including responding to other C-BUS commands (except General
Reset, $01).
When b5 is set, the device will be held in reset and all signal processing will cease (including AuxADC
operation.
When b3 is set the Xtal is disabled. When b3 is subsequently cleared, it may take some time for the clock
signal to become stable, hence care should be taken in using this feature.
8.1.18 Mode Control – $C1 write
15
0
14
13
12
11
10
9
8
7
0
6
0
5
0
4
3
2
1
0
Audio
NWR
Inband Modes
Data Mode
Idle/Rx/Tx
b15
reserved
0
b14
Audio Enable
0 = off
1 = enabled (uses Input 1 source)
1 = Input 2
b13
b12
NWR Source
NWR Enable
0 = Input 1
0 = off
1 = enabled (enables both WAT and SAME)
b11
b10
b9
Inband Source
Audio Generator Enable
reserved
0 = Input 1
0 = off
0
1 = Input 2
1 = enabled
b8
DTMF Enable
0 = off
1 = enabled
b7
b6
b5
reserved
reserved
reserved
0
0
0
b4
b3
b2
Modem Source
reserved
Modem Enable
0 = Input 1
0
0 = off
1 = Input 2
1 = enabled
b1-0
Operational mode
00 Idle
01 Rx
10 Tx
11 reserved
Changes to the settings of the bits in this register are implemented as soon as they are received over the
C-BUS (note that the C-BUS has a potential latency of up to 250μs).
In Tx mode, it is not permissible to set BOTH b3 and b2 at the same time.
In Tx mode, it is only permissible to select ONE of the following at any time:
Audio
Inband Signalling
DSC Signalling
Note that if the Audio Processing bit (b14) is set at the same time as an Inband signalling bit in Tx mode,
the Inband signal will be subjected to a 6dB gain.
It is essential that changes to the Programming register and the Audio Control register are completed
before entering Rx or Tx mode.
© 2010 CML Microsystems Plc
43
D/885/3
CMLMICRO [ CML MICROCIRCUITS ]
