is there way to control dss output bits?

is there way to control dss output bits?

[Alex Tomas]

Hi,

I'm trying to build simple DAC to generate RGsB signal on a beagleboard.
say, the output is filled with green, then at "green" pins I get 1 all the time
while I'd like to get 0 while hsync/vsync are active. is it possible with OMAP?
I found UNUSEDBITS in the documentation, but that seem to be related to
RFBI and not to regular parallel output ?

thanks, Alex

Re: is there way to control dss output bits?

[Tomi Valkeinen]

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On Mon, 2012-03-19 at 12:10 +0300, Alex Tomas wrote:
> Hi,
> 
> I'm trying to build simple DAC to generate RGsB signal on a beagleboard.
> say, the output is filled with green, then at "green" pins I get 1 all the time
> while I'd like to get 0 while hsync/vsync are active. is it possible with OMAP?
> I found UNUSEDBITS in the documentation, but that seem to be related to
> RFBI and not to regular parallel output ?

I'm not aware of such functionality. Why do you care what the green pins
are during hsync/vsync? The color pins should be used only when the
data-enable pin indicates that there's valid data there.

 Tomi



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Re: is there way to control dss output bits?

[Alex Tomas]

On Mon, Mar 19, 2012 at 12:18 PM, Tomi Valkeinen <tomi.valkeinen@ti.com> wrote:
>> I'm trying to build simple DAC to generate RGsB signal on a beagleboard.
>> say, the output is filled with green, then at "green" pins I get 1 all the time
>> while I'd like to get 0 while hsync/vsync are active. is it possible with OMAP?
>> I found UNUSEDBITS in the documentation, but that seem to be related to
>> RFBI and not to regular parallel output ?
>
> I'm not aware of such functionality. Why do you care what the green pins
> are during hsync/vsync? The color pins should be used only when the
> data-enable pin indicates that there's valid data there.

I see... I tried to re-used a schema which relies on this as that primitive DAC
basically sums "color" current with "sync" current.

(tested that on samsung chips).

thanks, Alex