Messages in this thread | | | From | Prabhakar Lad <> | Date | Thu, 4 Oct 2012 19:23:26 +0530 | Subject | Re: [PATCH] ARM: davinci: dm644x: fix out range signal for ED |
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Sekhar
On Thu, Oct 4, 2012 at 12:43 PM, Sekhar Nori <nsekhar@ti.com> wrote: > On 10/4/2012 10:22 AM, Prabhakar Lad wrote: >> Hi Sekhar, >> >> On Wed, Oct 3, 2012 at 4:08 PM, Sekhar Nori <nsekhar@ti.com> wrote: >>> On 10/3/2012 12:05 PM, Prabhakar wrote: >>>> From: Lad, Prabhakar <prabhakar.lad@ti.com> >>>> >>>> while testing display on dm644x, for ED out-range signals >>>> was observed. This patch fixes appropriate clock setting >>>> for ED. >>> >>> Can you please clarify what you mean by "out range signal"? Are there >>> any user visible artifacts on the display? What was the clock being >>> provided earlier and what is the value after this patch? >>> >>> Also, is the issue severe enough that this patch should be applied to >>> stable tree as well? >>> >> Ideally a clock of 54Mhz is required for enhanced definition to >> work, which it was actually set to but while testing I noticed >> out-of-range signal. The out-of-range signal is often caused >> when the field rate is above the rate that the television will handle. >> When this is the case the TV or monitor displays "Out-Of-Range Signal". >> >> Reducing the clock fixed it. now the clock is set to 27Mhz. > > So, is the requirement for ED 54MHz or lower? Still trying to explain > myself how 27MHz is working where a 54MHz is required. I guess there is > also a lower limit on what the frequency should be? > Ideally its 54Mhz, but I see in the datasheet for AD7342/3 [1] it can also work at 27Mhz too.
Regards, --Prabhakar
[1] http://www.analog.com/static/imported-files/data_sheets/ADV7342_7343.pdf
> Sorry I am not familiar will all the video concepts, hence the questions. > > Thanks, > Sekhar
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