Re: [PARPORT] DMA in ECP and EPP mode

Date: Fri Apr 20 2001 - 17:47:24 EDT

  • Next message: Ian Stirling: "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?
    > Well, they are just different protocols. With both modes the
    > peripheral gets to say whether it has data to transfer, AFAIR.

    ECP is much easier to implement with firmware on a microcontroller than is
    EPP. The ECP timing requirements are much more tolerant of delays. Thus
    the Linux driver is able to offer a software emulation of ECP, while it
    cannot emulate EPP in software. It is also easier to implement
    bi-directional exchanges with ECP. These lower electronics and
    development costs tend to increase ECP popularity.

    -- To unsubscribe, send mail to: --
    -- with the single word "unsubscribe" in the body of the message. --

    This archive was generated by hypermail 2b29 : Fri Apr 20 2001 - 17:52:44 EDT