Vybrid ProcessorsのトピックRe: VIU FID-input purpose

VIU FID-input purpose

kef2 — Thu, 05 Sep 2013 09:05:26 GMT

Hello.

I wonder what's the purpose of FID input. RM and datasheet list it, but there's no description, except

• FID must change state 3 Hsync pulses into Vsync.

I don't understand ^^ it. Is there some timing diagram with specified time delays? Is FID signal required and limits sensor choice?

Also I wonder when

FIELD_IRQ and VSTART_IRQ interrupts are supposed to happen. I can't find information in RM.

Thanks

Re: VIU FID-input purpose

naoumgitnik — Fri, 06 Sep 2013 02:50:12 GMT

Hello Edward,

This signal is a part of a standard interface hence not described in our documentation (very briefly, it only indicates odd/even frame required for the de-interlacing feature).

It is not mandatory, and the VIU interface actually works only based on Hsync and Vsync. If not provided to Vybrid, our VIU driver code (part of the BSP) should be modified - the FID input interrupt ignored, and its state is "do not care".

Regards, Naoum Gitnik.

Re: VIU FID-input purpose

kef2 — Fri, 06 Sep 2013 07:27:08 GMT

Dead Naoum,

thank you very much for your reply. It answers my concern about FID pin usage, but I still have questions.

Which "standard interface" do you refer? While choosing sensors I saw different pin names used by different CMOS camera vendors. So at least they are not following standards for sync. signals names. I neither don't see any standards mentioned in VIU3 block 57.2 Features section. Could you specify what standard should I study, or maybe camera chip which documents FID and other "standard" signals?

It is also still not clear when FIELD_IRQ and VSTART_IRQ interrupts are supposed to happen. I lack at least short description for each VIU3 module interrupt.

You mentioned "our VIU driver code (part of the BSP)". Could you enlighten which BSP do you refer? MQX?

Thanks

Re: VIU FID-input purpose

naoumgitnik — Fri, 06 Sep 2013 20:37:38 GMT

Hello Edward,

I am not a video expert but would recommend to take a look at the following special-purpose component - NTSC/PAL/SECAM Video Decoder (http://www.mouser.com/ds/2/405/sles209e-205815.pdf). It has a similar interface (and the FID signal with description as well), and the ITU-R Recommendation BT.656, also called ITU656 ( formally CCIR-656) is mentioned in it (see ITU-R BT.656 - Wikipedia, the free encyclopedia). Even in this brief description the Interlaced video technique is mentioned, relevant for the FID signal.

Hopefully it helps.

Regards, Naoum Gitnik.

Re: VIU FID-input purpose

kef2 — Mon, 09 Sep 2013 06:46:56 GMT

Thanks.

I still would love to see FID input description in Reference Manual, along with description of VIU3 module interrupts.