FX828 Datasheet, PDF (15/34 Pages) CML Microcircuits – CTCSS/DCS/SELCALL Processor

CTCSS/DCS/SELCALL Processor
FX828
AUDIO CONTROL Register (Hex address $8A)
This is a 16-bit register. Byte (1) is sent first. Bits 0 - 5 of the first byte in this register are used to set the
attenuation of the Modulator 1 amplifier and bits 0 - 5 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
BYTE 2
543210
0XXXXX
100000
100001
100010
100011
100100
100101
100110
100111
101000
101001
101010
101011
101100
101101
101110
101111
110000
110001
110010
110011
110100
110101
110110
110111
111000
111001
111010
111011
111100
111101
111110
111111
Mod. 1 Attenuation
Disabled (V_BIAS)
>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
543210
0XXXXX
100000
100001
100010
100011
100100
100101
100110
100111
101000
101001
101010
101011
101100
101101
101110
101111
110000
110001
110010
110011
110100
110101
110110
110111
111000
111001
111010
111011
111100
111101
111110
111111
Mod. 2 Attenuation
Disabled (V_BIAS)
>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 SUMMING 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".
SELCALL TX Register (Hex address $8D)
This is a 16-bit register. Byte (1) is sent first.
When the SELCALL transmitter is enabled, bits 0 to 12 control the frequency of the transmitted SELCALL
tones according to the formula overleaf:
© 2009 CML Microsystems Plc
15
D/828/4