TI-H: Re: TI-Hardware Digest V1 #1289
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TI-H: Re: TI-Hardware Digest V1 #1289
I recommend you to read the mc68328 users manual There says a method to manage LCD with
DMA. I think the uC in the ti89 uses a similar fashion. It's only a conjeture because
the manual for the SC can't be found. But the time measures says it's possible.
How much time ?, i think between 2 and 3% of the total time.
Date: Wed, 8 Nov 2000 16:47:24 -0800 (PST)
> From: Jeff Flanigan <propalo@yahoo.com>
> Subject: TI-H: TI-89 LCD Driver
>
> I have a few questions about the LCD driver for the
> 89. (I'm not sure whether to ask them here or in the
> 89 asm list, but I'll give it a shot here.)
>
> I assume that the driver doesn't use built-in graphics
> RAM, because if it did then grayscale wouldn't work.
> Therefore, it must use the RAM that it is assigned to
> draw its image from, and not mask over it. Does it
> use bus mastering to read the RAM, or what? How much
> time does an entire read take? Can the address it
> draws its image from be in the flash ROM area? Do its
> reads to the RAM or ROM go through the U8 chip that
> controlls flash protection? Is this why the TI-OS
> disables LCD update when unprotecting the ROM? Just a
> few questions... maybe some of you know the answers
> or maybe I will just have to try some tests. Just
> some food for thought. :)
>
> - - Jeff Flanigan
>
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