CMX138 CML Microcircuits, CMX138 Datasheet - Page 56

• Manufacturer Part Number: CMX138
• Description: Audio Scrambler and Sub-Audio Signalling Processor
• Manufacturer: CML Microcircuits

Audio Scrambler and Sub-Audio Signalling Processor
9.2.5
Default values:
$C8 (P4.0)
Fine input gain adjustment should be kept within the range 0 to -3.5dB. This adjustment occurs after the
coarse input gain adjustment (register $B0). This setting affects both MIC and DISC inputs.
$C8 (P4.1)
This register is reserved and should be cleared to '0'.
$C8 (P4.2-3)
Fine output gain adjustment should be kept within the range 0dB to -3.5dB ($000 to $2A73). This
adjustment occurs before the coarse output gain adjustment (register $B1). Alteration of Fine Output
Gain 1 will affect the gain of the AUDIO output, and Fine Output Gain 2 will affect the MOD output.
© 2008 CML Microsystems Plc
Gain = 20 × log([32768-OG]/32768)dB. OG is the unsigned integer value in the ‘Fine Output Gain’ field.
P4.10
P4.0
P4.1
P4.2
P4.3
P4.0
P4.1
P4.2
P4.3
P4.4
P4.5
P4.6
P4.7
P4.8
P4.9
Bit:
Bit:
Bit:
Gain = 20 × log([32768-IG]/32768)dB. IG is the unsigned integer value in the ‘Fine Input Gain’ field.
Bit:
Program Block 4 – Gain and Offset Setup:
P4.0
P4.1
P4.2
P4.3
P4.4
15
15
15
1
0
0
0
15
0
0
1
0
0
0
0
0
0
0
0
14
14
14
Fine Output Gain 1 and Fine Output Gain 2
$8000
$0000
$0000
$0000
$0000
Fine Input Gain
0
Reserved
0
0
0
14
0
0
0
0
0
0
0
0
0
0
0
13
13
13
13
12
12
12
12
11
11
11
11
Special Programming Register (Production Test Only)
10
10
10
10
Fine Output Gain 1 – AUDIO (unsigned integer)
Fine Output Gain 2 – MOD (unsigned integer)
Limiter Setting (all '1' s = Vbias +/- AV
9
9
9
Fine Input Gain (unsigned integer)
P4.5
P4.6
P4.7
P4.8
P4.9
P4.10
9
Output 1 Offset Control - AUDIO
Output 2 Offset Control - MOD
Page 56
Fine Output Gain 1 - AUDIO
Fine Output Gain 2 - MOD
8
8
Reserved - clear to '0'
8
Audio Filter Sequence
Reserved - clear to '0'
8
Ramp Rate Control
Fine Input Gain
$0000
$0000
$3FFF
$119A
$004B
$0000
7
7
7
reserved
7
6
6
6
6
5
5
5
5
4
4
4
DD
4
/ 2)
3
3
3
3
2
2
2
2
D/138_FI1.0/5
1
1
1
1
CMX138
0
0
0
0