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ADV7181C VGA Set-up

Question asked by rsavage on Jul 19, 2012
Latest reply on Jul 26, 2012 by GuenterL



I am attempting to convert VGA 640x480@60Hz (with seperate HS\VS Syncs) to SDR 20-bit 4:2:2 YCrCb using the ADV7181C.


I have successfully converted Composite and Y\C video to SDR 20-bit 4:2:2 YCrCb using the SD Processor, i.e. with the same hardware.


I have attempted a number of register settings and I have been unable to output anything from the 7181C; no clock or data.


I have listed below the Register Settings I have been using, which were deduced from the ADV7181C Datasheet, the ADV7181C_ADV7181C@_ADV7341-VER.8bit-Out-Encoder.txt file and the AN-0978 Rev.0 App Note.


03    04    Outputs Enabled, 20-bit @ LLC2 4:2:2 LLC selected

04    4B   Force HS, VS, F Active

05    02    PRIM_MODE = 0010b for GR Mode Page 216 of Datasheet

06    08    Video Standard = VGA (640x480@60) Page 217 of Datasheet

C3    56    Manually Route RED to Ain5 and GREEN to Ain6

C4    84    Manually Route BLUE to Ain4 and Switch On Manual Muxing

3A    11    LLC Range - Latch Clock to 13.5MHz to 55 MHz \ ADC3 Powered Down

3B    81    Use Internal Bias Resistor

3C    5C    Charge Pump set to 100b (350uA) for VGA 640x480, from Table 10, Page 42 of Datasheet

6B    C1    HSync and Field output and 20-bit output requested, as per Page 232 of Datasheet

7B    1D    Set for RGB Inputs, Page 235 of Datasheet

87    E3

88    20    PLL_DIV_RATIO set to 800 = 0x320 as per Table 10 of Datasheet (Page 42)

8A    90    VCO_RANGE Manually set to 00 = 21MHz Max, as per Table 10 again

8F    03

90    8E    Automatic LLC_PAD_SEL and Line of Video is 910 (0x38E) x 28,63636MHz Clocks, as per AN-0978

1D    47    28MHz Crystal Mode set

86    1B    New STDI "Line Count" Mode used

73    10    Automatic Gain Mode

85    02    Detector in Continuous Mode

F4    3F    Drive Strength to Max.


Any assistance would be greatly appreciated.