Datasheet
ADV7189B
Rev. B | Page 13 of 104
ANALOG FRONT END
ANALOG INPUT MUXING
04983-0-006
AIN1
AIN12
AIN7
AIN6
AIN2
AIN11
AIN8
AIN5
AIN3
AIN10
AIN9
AIN4
AIN4
AIN9
AIN10
AIN3
AIN5
AIN8
AIN11
AIN2
AIN6
AIN7
AIN12
AIN1
AIN3
AIN9
AIN4
AIN10
AIN5
AIN11
AIN6
AIN12
AIN2
AIN8
AIN5
AIN11
AIN6
AIN12
1
0
1
0
1
0
ADC_SW_MAN_EN INSEL[3:0]
ADC0_SW[3:0]
ADC1_SW[3:0]
ADC2_SW[3:0]
INTERNAL
MAPPING
FUNCTIONS
ADC2
ADC1
ADC0
Figure 6. Internal Pin Connections
The ADV7189B has an integrated analog muxing section that
allows more than one source of video signal to be connected to
the decoder.
139HFigure 6 outlines the overall structure of the input
muxing provided in the ADV7189B.
As can be seen in
140HFigure 6, there are two different ways in which
the analog input muxes can be controlled:
• Control via functional registers (INSEL). Using INSEL[3:0]
simplifies the setup of the muxes, and minimizes crosstalk
between channels by pre-assigning the input channels.
This is referred to as ADI recommended input muxing.
• Control via an I
2
C manual override (ADC_sw_man_en,
ADC0_sw, ADC1_sw, ADC2_sw). This is provided for
applications with special requirements, for example,
number/combinations of signals that would not be
served by the pre-assigned input connections. This is
referred to as manual input muxing.
Refer to
141HFigure 7 for an overview of the two methods of
controlling the ADV7189B’s input muxing.
ADI Recommended Input Muxing
A maximum of 12 CVBS inputs can be connected and decoded
by the ADV7189B. As seen in
142HFigure 5, this means the sources
have to be connected to adjacent pins on the IC. This calls for a
careful design of the PCB layout, for example, ground shielding
between all signals routed through tracks that are physically
close together.
INSEL[3:0] Input Selection, Address 0x00[3:0]
The INSEL bits allow the user to select an input channel as well
as the input format. Depending on the PCB connections, only
a subset of the INSEL modes are valid. The INSEL[3:0] does
not only switch the analog input muxing, it also configures the
standard definition processor core to process CVBS (Comp),
S-Video (Y/C), or component (YPbPr) format.