ADV7189B SFL to ADV7179 SCRESET/RTC  for Subcarrier Lock?

Can ADV7189B SFL drive ADV7179 SCRESET/RTC for Subcarrier Lock?


- Video ADV7189B decoder Pixel Data Out P9-P2 to ADV7179 encoder inputs P7-P0
- Encoder Input SCRESET / RTC is connected to the output of the decoder SFL.
- LLC1 output (output of 27 Mhz) of the decoder is connected to the Clock input of the Encoder.
- HSYNC; VSYNC; BLANK encoder inputs are not used.

With this, and setting:
a) External Control Out (B1) 1 in the encoder and MR21 = 1 and MR22 = 1 in the decoder, the output signal of the subcarrier ADV7179 is not genlocked.
b) With MR22 = 0 and MR21 = 1; chroma signal is jumping + -180 degrees permanently.

Is there any chance to genlock the ADV7179 subcarrier output with the input signal to the decoder?

(All values are in hexadecimal)


Case 1:
Encoder ADV7179
Mode Register 0 = 05
Mode Register 1 = 10
Mode Register 2 = 06
Mode Register 3 = 00
Mode Register 4 = 00
Timing Register 0 = 00
Timing Register 1 = 00
Decoder ADV7189B
Extended output control (Address 04) = C2
Resample Control (Address 41) = 50
Result: DSC_0032_2.jpg => Chroma genlock lost


Case 2:
Encoder ADV7179
Mode Register 0 = 05
Mode Register 1 = 10
Mode Register 2 = 02
Mode Register 3 = 00
Mode Register 4 = 00
Timing Register 0 = 00
Timing Register 1 = 00


Decoder ADV7189B
Extended output control (Address 04) = C2
Resample Control (Address 41) = 50
Result: Chroma is jumping +-180 degrees

  • 0
    •  Analog Employees 
    on Aug 24, 2011 9:12 PM over 9 years ago

    Firstly these are older ADI products and we would be advising that the newer ADV7184/8 and ADV734x or ADV739x products are used. It is not possible to genlock ADI decoder and encoder products. Our SFL feature provides color sub carrier frequency lock only. When the encoder gets a perfect 27Mhz clock SFL will not be required. However when the encoder gets an LLC clock (27Mhz +/- 5%) from the decoder  then the SFL stream can be used to send a 'correction' so that the proper color sub carrier frequency is generated.