Marine VHF Audio and Signalling Processor
CMX885
8.1.10 Input Gain and Output Signal Routing – $B1 write
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
0
0
Input 2 Gain
Input 1 Gain
MOD1
Source
MOD2
Source
AUDIO
Source
Input 1
Routing
Input 2
Routing
b12
b15
0
b11
b14
0
b10
b13
0
Input 1 Gain
Input 2 Gain
0dB (default)
3.2dB
0
0
1
b7
0
1
MOD2 Source
bias -> MOD2 (default)
Output 2 -> MOD2
0
0
1
1
0
1
6.4dB
9.6dB
1
0
0
12.8dB
1
1
1
0
1
1
1
0
1
16.0dB
19.2dB
22.4dB
b6
0
1
AUDIO Source
bias -> AUDIO (default)
Output 1 -> AUDIO
b9
0
0
b8
0
1
MOD1 Source
bias (default)
bias
1
1
0
1
Output 1 -> MOD1
Output 2 -> MOD1
b5
b3
0
b4
b2
0
Input 1 Signal Routing
Input 2 Signal Routing
bias (default)
DISCN
0
1
1
0
ALTN
1
1
MICN
Output 1 and Output 2 signal sources are also defined in section 8.1.3.
Bits 1, 0 are reserved – clear to 0.
There are a number of applications where it may be desirable to split the processing across both inputs,
such as monitoring two RF receivers, in which case, Input 1 could be routed from the DISCN input with
voice and DSC or NWR processing set to Input 2 from the ALTN input.
Similarly, for the output routing, under normal operation, In Tx Mode, Output 1 would be routed to MOD1
and Output 2 to MOD2. The signals that appear on Output 1 and Output 2 are defined in the Tx MOD
Mode register, $A7:b14 to b12.
If the AUDIO output is selected in Tx mode (using b6) it will present the signal that has been routed to
Output 1. This can be used for “sidetone” when transmitting Inband signalling in 1 or 2-point modulation
modes. In Rx mode, the Audio Process is automatically routed to Output 1.
An audio output is only available when in Rx or Tx Mode.
8.1.11 Reserved – $B2 write
8.1.12 Reserved – $B3 write
8.1.13 Reserved – $B4 8-bit read
© 2010 CML Microsystems Plc
41
D/885/3
CMLMICRO [ CML MICROCIRCUITS ]
