Picture in Picture circuit

[jdahl]

Hello guys.
We are two students that are doing a project*. We have posted a few posts here earlier, and got a lot of help.
Now we are almost done with the circuit, and wondering if some of you can have a look at it and give us some feedback and/or comments.

We have also a few questions about some pins on the pvp9390 (picture in picture IC.)

Pin 6, SEL - Fast blanking output for PIP, black screen out? cvbs?
Pin 38, INTR - Interrupt output
Pin 41, VSP - Vertical sync for parent channel
Pin 42, HSP - Horizontal sync for parent channel this is input signals, The camera we are using gives out CVBS, does this signal contain the V/H sync signal?

I know, there are alot of questions
Thanks for any feedback!

* The project it to connect two cameras and look at them at one tv screen.
Like this

I`m also adding the PVP9390 datasheet if any of you want to see it (1.4 MB) **broken link removed** the pin description are on page 91

NB: I also added the schamatic for the circuit, it`s in eagle, rename the *.asc to *.sch if you wanna look at it..

 

[furyfax]

No one got any input? We are really struggling with the HSP and the VSP. Hope someone can help us out.

 

[Nigel Goodwin]

You use a sync-seperator to seperate the sync signals from the composite video - you can do it easily with discrete components, or there are some very simple to use IC ones (which is probably a better idea).

 

[furyfax]

This is what I thought, but we constantly have 2 CVBS signal which go into this chip, therefore I don't know wich signal to get the sync from? Any idea ?

 

[Nigel Goodwin]

Your post above says 'SYNC FOR PARENT CHANNEL', so presumably it's the main one.

 

[furyfax]

Hmm.. I guess we'll just have to try a signal.. We don't have a "main" signal. They're both equal to us, if you know what i mean..

 

[Nigel Goodwin]

Hmm.. I guess we'll just have to try a signal.. We don't have a "main" signal. They're both equal to us, if you know what i mean..

It's called 'Picture IN Picture', so the main one is the background picture that the other is inserted into.

 

[furyfax]

My mistake, I was a bit confused. We're using a microcontroller to send commands to the PiP circuit, at first I thought this would influence what picture is main, but it shouldn't have anything to say.

Any IC you would recommend for extraction of the sync ?

 

[Nigel Goodwin]

Check out the Elantec devices at **broken link removed**

 

[furyfax]

Thanks for all help so far Nigel, we really appreciate it.
Do you have any idea how to connect pin 6 "SEL". It says in the datasheet that it's "OBL = obligatory; connect as described in circuit diagram" and it`s short description is "Fast blanking output for PIP"
If you look at page 97 in the datasheet, there's not much help in the circuit diagram.

 

[Nigel Goodwin]

Presumably it blanks off the main source in order to insert the PIP information?.

 

[furyfax]

I'm uncertain if we need this function, but it says that it's obligatory. Any ide how to connect this?

 

[Nigel Goodwin]

I'm uncertain if we need this function, but it says that it's obligatory. Any ide how to connect this?

It connects to some other part of your circuit, the PIP chip is only a small part of the complete design - I would imagine it connects to the decoder IC, the fast blanking input for teletext insertion?, which is where the RGB from the PIP chip enters as well (the teletext RGB input).