Manual Input Muxing Overview; Manual Input Muxing - Analog Devices ADV7850 Hardware Manual

Function
ain_sel[2:0]
Code
000 
001
010
The emb_sync_sel_1 signal should be considered as the main synchronization input for this muxing arrangement, and the
emb_sync_sel_2 signal will be monitored in parallel through the second synchronization stripper.

5.5 MANUAL INPUT MUXING OVERVIEW

By accessing a set of manual override muxing registers, the analog input muxes of the ADV7850 can be controlled directly. This is referred
to as manual input muxing (refer to Section 5.5.1).
Notes:
Manual input muxing overrides all other input muxing control bits, for example, ain_sel[2:0]. The manual muxing is activated
•
by setting the adc_switch_man. It only affects the analog switches in front of the ADCs.
have to be set so the follow on blocks process the video data in the correct format.
• Manual input muxing only controls the analog input muxes.
• The ADI recommended input combinations are designed to minimize crosstalk between input channels. When using the
manual input muxing, special care must be taken by the user/PCB designer to take care of cross coupling.
Not every input pin can be routed to any ADC. There are restrictions in the channel routing imposed by the analog signal routing inside
the IC (refer to Section 5.5.1).

Manual Input Muxing

5.5.1
The manual muxing controls listed in this section configure the analog inputs. These controls should be used to override the auto
configuration described in Section 5.4.
Note:
The following rules must be adhered to when selecting analog input routing to the ADCs:
•
CVBS signals must always connect to ADC0.
• Y/C signals must always connect to ADC0 and ADC1. Y must connect to ADC0 and C must connect to ADC1.
•
YPrPb signals must always connect to ADC1, ADC2 and ADC3. Y must connect to ADC1, Pr must connect to ADC2 and Pb
must connect to ADC3.
• RGB signals must always connect to ADC1, ADC2 and ADC3. G must connect to ADC1, R must connect to ADC2 and B must
connect to ADC3.
Refer to Table 5 for more information.
adc_switch_man, AFE, Address 0x02[7]
This control is used to enable manual input muxing to the ADCs.
Function
adc_switch_man
0 
1
Once adc_switch_man is set to 1, the following controls take effect.
Rev. A May 2012
Description
ADC0|ADC1|ADC2|ADC3|EMB_SYNC_SEL1|EMB_SYNC_SEL2
NC | Ain1 | Ain2 | Ain3 |
NC | Ain4 | Ain5 | Ain6 |
Ain10 | Ain7 | Ain8 | Ain9 |
Description
Automatic muxing
Manual muxing
Sync1 | Sync2
Sync2 | Sync1
47
prim_mode[3:0] and vid_std[5:0]
ADV7850
still