tda8295 NXP Semiconductors, tda8295 Datasheet - Page 31

• Manufacturer Part Number: tda8295
• Description: Tda8295 Digital Global Standard Low If Demodulator For Analog Tv And Fm Radio
• Manufacturer: NXP Semiconductors

NXP Semiconductors
TDA8295_1
Product data sheet
9.3.8 Digital IF AGC functions
Table 26.
Legend: * = default value.
Bit
7
6
5 to 1 D_IF_AGC_AVG[4:0] R/W
0
Symbol
D_IF_AGC_CORR
D_IF_AGC_MODE
RST_INT
D_IF_AGC_SET_1 register (address 12h) bit description
Digital global standard low IF demodulator for analog TV and FM radio
Rev. 01 — 4 February 2008
Access Value
R/W
R/W
R/W
0
1*
0*
1
0 0001
0 0010
0 0100
0 1000
1 0000*
0*
1
Description
This determines the condition under which the
digital IF AGC switches to Correlated mode. If
D_IF_AGC_CORR is HIGH, the digital IF AGC
works in a Correlated mode only if N_H_LOCK,
F_H_LOCK and V_LOCK are active (see
H/V PLL read-out in
Correlated mode is activated when N_H_LOCK
and V_LOCK are active.
If HIGH, the digital IF AGC detection and gating
is done during the back porch of the video
signal. This Detection mode can be used for all
standards (also L/L-accent standard) without
impact on the IF AGC loop speed.
With D_IF_AGC_AVG the number of lines for
averaging during the digital IF AGC gating
window is set. This is only valid if the AGC mode
is correlated (H/V PLL locked). With the
averaging, the line noise at low RF levels is
reduced.
The digital IF AGC integrator can be set to zero
(i.e. lowest digital IF AGC gain). This option can
be used for debugging purposes.
H-lock + V-lock
H-lock + fast H-lock + V-lock
peak sync AGC (slow peak white L/L-accent
standard)
black level AGC detection
2 samples
4 samples
8 samples
16 samples
32 samples
normal operation
reset IF AGC integrator
Table
44). If LOW, the
TDA8295
© NXP B.V. 2008. All rights reserved.
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