We replaced the ADV7189 video decoder by the ADV7189B. Now the VBI data (teletext in PAL signal) on the SD output is not correct any more. Do we need to change particular register settings to make the decoder transparent to VBI data? Is there also a changeover document available?
We already enabled the VBI_EN bit to make sure that the VBI data is passed through with only a minimum amount of filtering. Also we enabled the BL_C_VBI bit to ensure the chroma will be blanked during VBI.
Even ADV7189B is a not recommended for new designs part. I'll get an expert on the part to comment.
Hi all, you need to transition to the ADV7188. We have the capability on that part to filter of pass VBI data.
We have products with the ADV7189B in the field already and would like to offer our customers a solution by updating firmware.
So a transition to the ADV7188 is not a suitable solution for us. We will take it into account for new designs.
Hi, looking back through the documentation I would have expected that the VBI passthough and chroma VBI blanking controls should have worked the same between both the parts you mention. I will enquire more but information on this older generation of parts is limited. Are you sure that the back end is not blanking because of the extended V-sync which it may be getting?
Can you please explain what you mean by an extended V-sync which the back end may be getting?
The VBI output data from the ADV7189B is as follows:
* Some lines are passed correctly.
* Some lines are passed distorted.
* Some lines are switching between the correct VBI line and a line from the wrong field.
(maybe other patterns show other results)
We only use the pixel output port (P10 to P19) and the LLC1 clock output. So we don't use HS, VS, FIELD and SFL outputs.