MSP 34x7G
PRELIMINARY DATA SHEET
6.3.4. Register AD_CV
The use of this register is no longer recommended.
Use it only in cases where compatibility to the
MSP 34x7D is required. Using the STANDARD
SELECTION register together with the MODUS regis-
ter provides a more economic way to program the
MSP 34x7G
Table 6–9: AD_CV Register; reset status: all bits are “0”
AD_CV
(00 BBhex
Automatic setting by
STANDARD SELECT Register
)
Bit
[0]
Function
Settings
2-8, 0A-51hex
9
not used
must be set to 0
0
0
[1:6]
Reference level in case of Automatic Gain
Control = on (see Table 6–10). Constant gain
factor when Automatic Gain Control = off
(see Table 6–11).
101000
100011
[7]
Determination of Automatic Gain or
Constant Gain
0 = constant gain
1 = automatic gain
1
1
[8]
[9]
not used
must be set to 0
0
1
0
1
MSP-Carrier-Mute Feature
0 = off: no mute
1 = on: mute as de-
scribed in Section 2.2.2.
[10:15]
not used
must be set to 0
0
0
X: not affected while choosing the TV sound standard by means of the STANDARD SELECT Register
Note: This register is initialized during STANDARD SELECTION and is automatically updated when Automatic
Sound Select (MODUS[0]=1) is on.
Table 6–10: Reference values for active AGC (AD_CV[7] = 1)
Application
Input Signal Contains
AD_CV [6:1]
Ref. Value
AD_CV [6:1]
in decimal
Range of Input Signal
at pin ANA_IN1+
Terrestrial TV
1)
− Dual Carrier FM
− NICAM/FM
− NICAM/AM
2 FM Carriers
101000
101000
100011
40
40
35
0.10 − 3 Vpp
1)
1 FM and 1 NICAM Carrier
1 AM and 1 NICAM Carrier
0.10 − 3 Vpp
0.10 − 1.4 Vpp
(recommended: 0.10 − 0.8 Vpp
)
− NICAM only
1 NICAM Carrier only
1 or more FM Carriers
010100
100011
20
35
0.05 − 1.0 Vpp
1)
SAT
0.10 − 3 Vpp
1)
For signals above 1.4 Vpp, the minimum gain of 3 dB is switched, and overflow of the A/D converter may result. Due to the
robustness of the internal processing, the IC works up to and even more than 3 Vpp, if norm conditions of FM/NICAM or
FM1/FM2 ratio are supposed. In this overflow case, a loss of FM-S/N-ratio of about 10 dB may appear.
66
Micronas
MICRONAS [ MICRONAS ]
