DMA copy to CRAM

For anything related to VDP (plane, color, sprite, tiles)

Moderators: BigEvilCorporation, Mask of Destiny

Post Reply
Very interested
Posts: 408
Joined: Wed Dec 06, 2006 9:01 am
Location: Aix-en-Provence, France

DMA copy to CRAM

Post by ob1 » Sat Dec 30, 2006 8:59 pm

Has anyone already tried (and succeded) to DMA copy from VRAM (obviously) to CRAM ?
Would it be faster than a DMA transfer from ROM or Work RAM (obviously no) ?

Nevertheless, with DMA copy, the CPU can keep on working whereas with DMA transfer, it is stalled. I guess that for transferring data to CRAM (1024 bytes max), I don't have to worry about CPU stalling.

Very interested
Posts: 3004
Joined: Thu Nov 30, 2006 9:46 pm
Location: France - Sevres

Post by Stef » Sat Dec 30, 2006 9:56 pm

You just can't transfert from VRAM to CRAM.
When you do a DMA operation, you can only choose destination :
So during DMA "copy" operation, destinatin almost becomes the source.

Post Reply