Re: [PARPORT] Example Code

From: Andrew Hogue (hogue@cs.yorku.ca)
Date: Fri Mar 30 2001 - 09:37:04 EST

  • Next message: Tim Waugh: "Re: [PARPORT] Example Code"

    Hi,

    > A more efficient method is to use the block writes, a bit like you
    > indicate:
    >
    > > ioctl(fd, PPSETMODE, PARPORT_MODE_STUPID);
    > > write(fd, buffer, 100); /* no handshaking, no timeouts, just write
    > > data as fast as possible to the data port with only one context switch */
    >
    > But it still seems a bit strange to me to want to just write to the
    > data port as fast as possible without ever touching the control lines.
    >
    > Is there really a need for this?

    Actually, this is basically what I really need to do since my device is an
    analog to digital convertor and in order to set the state of the device
    and get any information from the device I have to send it data across the
    data lines. There's only one thing that doesn't touch the data lines and
    that is to check the Status pin. I guess this might cause a problem since
    it will introduce another mode switch but maybe 1 or 2 mode switches will
    be more efficient than 10 or whatever I have now... :)

    Thanks for all your help.

    -- Andrew

    >
    > (Currently, you can replace PARPORT_MODE_STUPID with
    > IEEE1284_MODE_{COMPAT,ECP,EPP} and have it to the obvious thing.)
    >
    > Tim.
    > */
    >

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