adv7188 Analog Devices, Inc., adv7188 Datasheet - Page 13

• Manufacturer Part Number: adv7188
• Description: Multiformat Sdtv Video Decoder With Fast Switch Overlay Support
• Manufacturer: Analog Devices, Inc.

ANALOG INPUT MUXING
The ADV7188 has an integrated analog muxing section that
allows connecting more than one source of video signal to the
decoder. Figure 6 outlines the overall structure of the input
muxing provided in the ADV7188.
As can be seen in Figure 6, the analog input muxes can be
controlled in two ways:
•
•
Figure 7 shows an overview of the two methods of controlling
input muxing.
FOR REQUIRED MUXING
By the functional register (INSEL). Using INSEL [3:0]
simplifies the setup of the muxes and minimizes crosstalk
between channels by preassigning the input channels. This is
referred to as the recommended input muxing.
By an I
ADC0_SW, ADC1_SW, ADC2_SW, and ADC3_SW). This
is provided for applications with special requirements, such
as number/combinations of signals that are not served by
the preassigned input connections. This is referred to as
manual input muxing.
SET INSEL[3:0] AND
CONFIGURATION
SDM_SEL[1:0]
2
C manual override (ADC_SW_MAN_EN,
YES
Figure 7. Input Muxing Overview
SEE TABLE 8 AND TABLE 9?
ANALOG SIGNALS
RECOMMENDED
INPUT MUXING;
CONNECTING
TO ADV7188
(ADC_SW_MAN_EN, ADC0_SW,
USE MANUAL INPUT MUXING
TO DECODE VIDEO FORMAT:
SCART (CVBS/RGB): 1111
SET SDM_SEL[1:0] FOR
CONFIGURE ADV7188
S-VIDEO/COMPOSITE
ADC1_SW, ADC2_SW,
SET INSEL[3:0] TO
AUTODETECT
YPrPb: 1001
CVBS: 0000
ADC3_SW)
Y/C: 0110
NO
Rev. A | Page 13 of 112
Recommended Input Muxing
A maximum of 12 CVBS inputs can be connected and decoded
by the ADV7188, meaning that the sources must be connected
to adjacent pins on the IC, as seen in Figure 5. This calls for a
careful design of the PCB layout, for example, placing ground
shielding between all signals routed through tracks that are
physically close together.
SDM_SEL [1:0], Y/C and CVBS Autodetect Mode Select,
Address 0x69 [1:0]
The SDM_SEL bits decide on input routing and whether
INSEL [3:0] is used to govern input routing decisions.
The S-video/composite autodetection feature is enabled using
SDM_SEL = 11.
Table 8. SDM_SEL [1:0]
SDM_SEL [1:0]
00
01
10
11
CVBS
Y/C
S-video/composite
autodetection
Mode
As per INSEL [3:0]
Analog Video Inputs
As per INSEL [3:0]
AIN11
Y = AIN10
C = AIN12
CVBS = AIN11
Y = AIN11
C = AIN12
ADV7188