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    SubjectRe: Disabling DMA with ICH10?
    Arjan van de Ven <> writes:

    > a single PIO instruction will NOT be interrupted by an interrupt.
    > And can easily take several microseconds (remember: 8Mhz bus
    > emulation)

    Not that long, there is no emulation there (except for port #80 (hex?)
    and similar). Normal 33 MHz access. But it's still slow, of course -
    every access takes at least 4(?) bus cycles (IIRC: address, initiator
    ready, device selected, target ready). No bursts (at least on typical
    x86 hw).

    Of course ICH10 AHCI isn't connected with PCI 33/32 bus.

    Anyway: PIO = bad idea.
    Krzysztof Halasa

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      Last update: 2009-09-29 14:31    [W:0.020 / U:3.448 seconds]
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