Re: [PARPORT] DMA in ECP and EPP mode

From: Ian Stirling (
Date: Fri Apr 20 2001 - 18:10:33 EDT

  • Next message: Fred Barnes: "Re: [PARPORT] DMA in ECP and EPP mode"

    > On 19 Apr, Tim Waugh wrote:
    > > On Wed, Apr 18, 2001 at 11:06:15PM +0200, Tommy Kjellqvist wrote:
    > >
    > >> Whitch mode can be expected to deliver the highest performance?
    > >
    > > It depends on your application, I think. ECP seems to be quite
    > > popular for newer devices though.
    > >
    > >> Is there any important differences between the two modes except the
    > >> fact that when transfering data from a peripherial to the host using
    > >> ECP the peripherial initiate the transfer?

    ECP can also be nicer to the host.
    EPP pretty much needs the host to bit-bang (well, pay more or less complete
    attention). ECP can be done with DMA.
    Throughput can be on the order of a meg a second plus.
    The host only needs to touch the data every 1/30th of a second or so, not
    every few us.

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