SAA7113H experience

A 9bit Y/C or CVBS input processor and 8bit video encoder devices both with I2C control

Both with support for all sorts of captioning, widescreen and ITU656 data formatting.

There is a wealth of information in the data sheets for those devices, including device circuits, however though do assume a few things you understand first:-

1/ Working with video (NOT PC graphics) 2/ Digital video standards 3/ What your system is doing.

I would suggest you read this book first

Video Demystified A Handbook for the Digital Engineer

By Keith Jack of (then) Brooktree ISBN 1-878707-09-4

These sorts of devices are not a general learner part to get to grips with understand digital video, its standards and system design for video processing.

I do assume your are also going to have some frame stores and processor control to interface with these devices?

Your system could almost be passthrough between the two devices or have frame stores or even hard disk drives or other digital video sources so no simple appliction note or design beyond somebodys product details will tell you a quarter of the design. Most of these products are likely to be in cost competitive or markets of high competition who are not likely to share the amount of knowledge required.

Consider that the book I mentioned is over 400 pages long and does not give detailed hardware and software designs down to each resistro or line of code. There are lots of block diagrams, standards and timing discussions.

--
Paul Carpenter          | paul@pcserviceselectronics.co.uk
    PC Services
              GNU H8 & mailing list info
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Paul,

Thanks for the response. I'm familiar with the video standards and will be using the 656 format to send data to an FPGA processing engine. Regarding the Philips chips it's things like the need (or not) for a filter on the

7129 outputs, what happens to the LLC output from the 7113 when it doesn't have any video input i.e. does it free run at 27MHz? I just trying to take some of the risk out of my initial work. I've not found the device data sheets that good to be honest with you.

Maybe I should have been specific with my initial post.

Regards,

Rog.

[snip]

If you don't have video going in it doesn't put out a sensible signal. I didn't bother to measure what it did put out because it was rubbish. The setup is the tricky thing and I had a lot of fun with these chips. The settings seem to go on forever and if you poke one bit of the timing another bit will need opposite tweaking. I'm not the hardware designer, I just suffered with the software. The circuit is not complicated and most of the clever stuff is in the settings. I recall that there was a magic resistor on the 7129 that wasn't documented but if you missed it off then the composite video output didn't work. The designers added low pass filters on all the outputs consisting of an inductor and a few other bits in a simple network.

Peter

Peter,

Thanks for that. The "magic resistor" would sound really amusing if it wasn't so important to the operation of the device. If you recall any more detail I'd obviously be interested to hear.

Thanks again,

Roger.

Hello Roger,

we (NEC) have used the SAF7113A (extended temperature version of the SAA7113A) for a demoboard of our graphics controller. You will find the manual at

and then enter "U17316EE1V0UM00" as the keyword to search for. In its attachment you will find the schematics of the board.

At the bottom of

you will find an application note "Operation of Ravin-E with V850 Devices" and some demo software in "V850EME2-RavinE-Demo.zip", which extends more on the V850E/ME2 processor and the graphics controller than on the

7113A. I could send you some small demoprograms for these boards, which initialize video capture with the SAA7113A.

Michael

Sorry, my memory was wrong, we used another encoder SAA7182A where a resistor had to be attached to TESTC. If it wasn't fitted then the composite output wouldn't work. We never found out why we needed it.

Peter

Thanks Peter.

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I may also have been a bit too hasty, having seen too many video related posts from those who fail to understand the basics of video or worst still how they are going to make camera devices do complicated tasks without working out the lighting and lenses required.

Video processing work involves a lot of sitting down and working out before putting the first part on the schematic, which many fail to realise.

I see you have had many useful replies after your further clarification and hope they provided the details required.

--
Paul Carpenter          | paul@pcserviceselectronics.co.uk
    PC Services
              GNU H8 & mailing list info
             For those web sites you hate

Thanks for the reply.

Rog.