Is anybody running 1280x1024@60 resolution on the Beagleboard XM?
I know this is overclocking and out of spec but will be interesting to
have a play with this resolution and hear comments from anybody that
has already done this.
I have a number of boards and don't mind if I blow one up pushing it
to the limits
I use this resolution on a BeagleBoard RevC3 with 2 DVI monitors:
Samsung 710T (17")
Dell 1908FPc (19")
No issues, working fine.
I don’t think you can fry the BB or the monitor trying this resolution. The worst thing that happens is the monitor doesn’t like the (tight) timing generated by the BB and doesn’t display any image. If your monitor supports lower refresh rates than 60Hz, and you can live with it, you can do even higher resolutions.
You can run this resolution in Angstrom, I actually trade to change
the u-boot.bin dvimode=640x480MR-16@60 to dvimode=1280x1024MR-16@60,
but boot fail, where I can found a u-boot.bin functional with this
resolution?
Because a contact at TI said that the DM3730 video output pixel clock
max in spec is 75MHz. To support 1280x1024 60Hz refresh ratio, 1280 x
1024 x 60 x 1.2 (black pixels by vesa standard) ~= 94MHz
The Beagle Board xM could show 1280x1024 output with 60Hz but please
note that it is overclocking and out of spec. This means TI does not
guarantee it. The maximum spec in spec would be 1280 x 800 60Hz.
Koen, have you tried 1280x1024@60 on the XM model, I see from your
posts that you have a lot of experience with the Beagleboard
but like say john
" The Beagle Board xM could show 1280x1024 output with 60Hz but please
note that it is overclocking and out of spec. This means TI does not
guarantee it. The maximum spec in spec would be 1280 x 800 60Hz."
But same problem when I trade to chanche this parameter but boot fail.
Hi,
Resolution is not set by the X server. The easiest way is to pass the right omapfb parameters to the kernel in uboot:
omapfb.mode=dvi:1280x1024MR-16 omapdss.def_disp=dvi
IIRC, you can also set resolution runtime with the omapfb/omapdss sysfs framework.
I have always understood that the maximum pixel rate was
83 MHz (original BB).
If you use the DSI PLL you get a 173MHz pixclock. Angstrom enabled that as default in the kernel, and has done that for years now. I have 1080p24 working nicely on a C4.
> Quoting Koen Kooi <koen@beagleboard.org>:
>
>> The supported pixclock is >170MHz on beagle
>
> Where is this specified?
In the omap3 TRM.
> I have always understood that the maximum pixel rate was
> 83 MHz (original BB).
If you use the DSI PLL you get a 173MHz pixclock. Angstrom enabled that as
default in the kernel, and has done that for years now. I have 1080p24
working nicely on a C4.
But 1920 x 1080 x 24 fps is a net rate of 48384000 triads/sec,
isn't it, so even when overheaded for the flyback periods,
it only requires a pixel clock in the ballpark of 50 MHz,
doesn't it?
72.something if I recall the hdmi specs correctly. The problem on omap3 is the the dividers you need to get a certain pixclock, using the 86.5 pixclock you will fail to get close to that