CTCSS Signalling Processor
FX818
AUDIO CONTROL Register (Hex address $8A)
This is a 16-bit register. Byte (1) is sent first. The six least significant bits of the first byte in this register are
used to set the attenuation of the Modulator 1 amplifier and the six least significant bits of the second byte in
this register are used to set the attenuation of the Modulator 2 amplifier, according to the tables below:
BYTE 1
0
BYTE 2
0
5
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
4
X
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
3
X
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
2
X
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
1
Mod. 1 Attenuation
5
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
4
X
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
3
X
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
2
X
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
1
Mod. 2 Attenuation
X
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
X
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Disabled (VBIAS
>40dB
12.0dB
11.6dB
11.2dB
10.8dB
10.4dB
10.0dB
9.6dB
9.2dB
8.8dB
8.4dB
8.0dB
7.6dB
7.2dB
6.8dB
6.4dB
6.0dB
5.6dB
5.2dB
4.8dB
4.4dB
4.0dB
3.6dB
3.2dB
2.8dB
2.4dB
2.0dB
1.6dB
1.2dB
0.8dB
0.4dB
0dB
)
X
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
X
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Disabled (VBIAS
>40dB
6.0dB
5.8dB
5.6dB
5.4dB
5.2dB
5.0dB
4.8dB
4.6dB
4.4dB
4.2dB
4.0dB
3.8dB
3.6dB
3.4dB
3.2dB
3.0dB
2.8dB
2.6dB
2.4dB
2.2dB
2.0dB
1.8dB
1.6dB
1.4dB
1.2dB
1.0dB
0.8dB
0.6dB
0.4dB
0.2dB
0dB
)
X = don't care
MOD1 ENABLE
(Bit 5, first byte)
When this bit is "1" the MOD1 attenuator is enabled.
When this bit is "0" the MOD1 attenuator is disabled (i.e. powersaved).
MOD2 ENABLE
(Bit 5, second byte)
When this bit is "1" the MOD2 attenuator and the SUMMER AMP are enabled.
When this bit is "0" they are both disabled (i.e. powersaved).
(Bits 7 and 6, first
and second bytes)
Reserved for future use. These should be set to "0"
ã 1997 Consumer Microcircuits Limited
13
D/818/4
CMLMICRO [ CML MICROCIRCUITS ]
