Roger Wolff (wolff@liberator.et.tudelft.nl aka WOLFF@DUTECAI.ET.TUDELFT.NL :-)
writes:
> Jeeez. If you want to advertize "High End" then you need to support more
> than 1024x768 at 24 bits per pixel. To me "High End" is at least 1280x1024,
> even at 24 bits per pixel. You don't even need more than 4Mb RAM to
> pull this off....
Hey, I said I was sorry for the commercial hype-speak ;-)
> According to SGS Thompson info I have at 1600x1280@70Hz, you need a video
> bandwidth of 1.3 * 1600 * 1280 * 70 = 186Mhz. With three bytes per pixel
> you need 560 Mb per second of video data. At 8 bytes per transfer you
> get a 70Mhz transfer rate of video data. This is slightly tricky, but
> not unusual for high end systems.
> Roger.
Umm, not quite. The TVP3020 does 24-bit video for lower resolutions only.
(Aside: just what constitutes "lower resolution" here is unclear, but the
news article said less than 1600x1280. It may be that it does support
24-bit true color at 1280x1024.)
At 1600x1280 it does 16 bits/pixel, so:
1.3 * 1600x1280 * 70(MHz) = 186Mhz
*2* bytes per pixel = 372MB / sec
divided by 8 bytes per bus transfer = 47 Mhz transfer frequency
which, being smaller, I would expect it to be somewhat easier to manage
than a 70Mhz transfer frequency. Of course, I'm still just a software
weenie (with a math degree ;-) and don't understand what this really means...
Russell Kent
--
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PO Box 655012 M/S 3624 kent@tifsim.pac.sc.ti.com
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