On 15 Feb 01 at 10:07, Trent Piepho wrote:
> On Thu, 15 Feb 2001, Alan Cox wrote:
> > > would take a seperate sequencer instruction to the bt848 DMA controller each
> > > time you want to reset the address back to the start. It's not going to work
> > > if you want to do this for every pixel, but you had a window 16 or 32 pixels
> > > wide in the FPGA's PCI address space, you could probably do it.
> >
> > Since the 848 will burst in order the obvious approach to me would be to map
> > the FPGA 32bit wide FIFO register across an entire 2Mb of PCI space. Just
> > forget to decode a few bits 8)
>
> Doesn't nvidia have a patent on this? I thought one of things they sued 3dfx
> over was mapping a register over an address range, so burst transfers that are
> designed to write blocks of memory can write to a single register efficiently.
As matrox does it since Millennium I (at least, I never looked at their ISA
cards) with their pseudoDMA window, I do not think that nvidia can ever win
such lawsuit.
Best regards,
Petr Vandrovec
vandrove@xxxxxxxxxx
