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DMA, specefications / documents

Posted: Sat Dec 06, 2008 5:46 pm
by kmtdk
Hi all
first: I HAVE seen the wiki, and the very first specefication of the "8237 DMA Chip controller", but realy, what about the "missing" parts ( UDMA, doubleword transferes of dma)
so i searched for the "82374 EISA controller", but not even intel has the specefications.
If someone knew where i could get them, or have them, i would be very please
also if you know more about, getting doubleword transfers and ultra dma transfere to work
( while searching, i found a thread, but inside the links was dated / broken )


KMT dk

Re: DMA, specefications / documents

Posted: Sat Dec 06, 2008 6:12 pm
by LoseThos
I use DWORD transfers with IDE/ATA port I/O. In the ICH7 documentation, I think it was, you learn to set-up I/O ports for SATA and stuff and I saw DWORDs mentioned.

Re: DMA, specefications / documents

Posted: Sat Dec 06, 2008 9:26 pm
by Brendan
Hi,
kmtdk wrote:first: I HAVE seen the wiki, and the very first specefication of the "8237 DMA Chip controller", but realy, what about the "missing" parts ( UDMA, doubleword transferes of dma)
so i searched for the "82374 EISA controller", but not even intel has the specefications.
AFAIK the 82374 EISA controller was rare, like the EISA bus itself - it probably didn't exist in most computers at the time (typically EISA was only used for servers until PCI replaced it soon after), and doesn't exist in any computers since.

You might be able to get an old chipset datasheet from Intel (e.g. for an EISA chipset from 1996 to 1998 perhaps), as their chipset datasheets include full documentation for everything in the chipset (including the ISA or EISA DMA controllers); but then you'd need detect if the chipset supports the 82374 EISA controller before using it (and use the traditional ISA DMA controller otherwise), and I seriously doubt you'll be able to find a computer to test it on.

Mostly, because the ISA DMA controller was only really useful for ISA devices (and the EISA DMA controller died before anyone noticed it existed), manufacturers of PCI devices built their own bus mastering into the device instead (including the IDE/ATA/SATA controller).


Cheers,

Brendan

Re: DMA, specefications / documents

Posted: Sun Dec 07, 2008 8:23 am
by kmtdk
So if I got it right now,
the dma controller dont take care of UDAM transferers
but the hdd controller does ???

KMT dk