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Is there any form of IRQ with the Stamp? — Parallax Forums

Is there any form of IRQ with the Stamp?

ArchiverArchiver Posts: 46,084
edited 2000-10-31 17:51 in General Discussion
Hello,

Does the BS2 have any form of an IRQ? I can't seem to
find it. If not, is there anything that closely
resembles the functionality of an IRQ in the
programming of a BS2?

Thanks,

Todd

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Comments

  • ArchiverArchiver Posts: 46,084
    edited 2000-10-31 04:55
    At 10/30/2000 -0800 08:43 PM, you wrote:
    >Hello,
    >
    >Does the BS2 have any form of an IRQ? I can't seem to
    >find it. If not, is there anything that closely
    >resembles the functionality of an IRQ in the
    >programming of a BS2?
    Hi Todd -

    Simply put - no. Polling is generally used in lieu of interrupts.

    Multiplexed inputs are sometimes used, where appropriate, for multiple ADC
    inputs. So too, parallel to serial shift registers - see Shiftin and
    Shiftout in the manual.


    >Thanks,
    >
    >Todd

    Regards,

    Bruce Bates


    >__________________________________________________
    >Do You Yahoo!?
    >Yahoo! Messenger - Talk while you surf! It's FREE.
    >http://im.yahoo.com/
  • ArchiverArchiver Posts: 46,084
    edited 2000-10-31 07:57
    On Mon, 30 Oct 2000, Todd Botner wrote:

    > Hello,
    >
    > Does the BS2 have any form of an IRQ? I can't seem to
    > find it. If not, is there anything that closely
    > resembles the functionality of an IRQ in the
    > programming of a BS2?

    If you don't have IRQ, you have to resort to device polling.

    Sean T. Lamont, CTO / Chief NetNerd, Abstract Software, Inc. (ServNet)
    Seattle - Bellingham - Vancouver - Portland - Everett - Tacoma - Bremerton
    email: lamont@a... WWW: http://www.serv.net
    "...There's no moral, it's just a lot of stuff that happens". - H. Simpson
  • ArchiverArchiver Posts: 46,084
    edited 2000-10-31 13:25
    Hi Todd,

    I haven't done this, but the LOSA mentions someone using the RESET pin as a
    form of interrupt. I haven't looked at it, but this would likely require a
    differentiator (in other words, a capacitor so you just get a pulse on the
    reset) and a latch connected to an input pin.

    On reset, you look at the latch. If it is 0, you just got reset. If it is 1,
    you just got interrupted. Of course, you can't return from the interrupt in
    any real sense. But you can service an external event and the go on with
    what you normally do. The LOSA is at -- I think -- www.hth.com/losa.

    Why not tell us _what_ you want to do and maybe someone can come up with an
    alternative to an IRQ.

    Regards,

    Al Williams
    AWC
    *Floating point math for the Stamp, PIC, SX, or any microcontroller:
    http://www.al-williams.com/awce/pak1.htm


    >
    Original Message
    > From: Todd Botner [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=nYzHhwoVAPt2Jr9_rPNiXH46z8Gk6aQ6T9eJzB3FOcE0rM61xbSsF-oF34fZaCAQXZbbprTpPUG2_UW0UAm0-g]contacttodd@y...[/url
    > Sent: Monday, October 30, 2000 10:43 PM
    > To: basicstamps@egroups.com
    > Subject: [noparse][[/noparse]basicstamps] Is there any form of IRQ with the Stamp?
    >
    >
    > Hello,
    >
    > Does the BS2 have any form of an IRQ? I can't seem to
    > find it. If not, is there anything that closely
    > resembles the functionality of an IRQ in the
    > programming of a BS2?
    >
    > Thanks,
    >
    > Todd
    >
    > __________________________________________________
    > Do You Yahoo!?
    > Yahoo! Messenger - Talk while you surf! It's FREE.
    > http://im.yahoo.com/
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2000-10-31 17:51
    Todd,
    Just finished a project where I used the technique Al mentioned. It isn't
    fast, but seems to be fairly consistent. I used a oneshot on the input
    because I needed the "event" to be controlled by the precise timing of the
    oneshot and couldn't wait to setup a PULSOUT. Of course, you loose
    everything "in process" and you need to make sure that your hardware
    initialization routines put all of your I/O pins where you need them. It
    isn't a replacement for an interrupt, but in my case, it got the job done.
    Mike


    At 07:25 AM 10/31/00 -0600, you wrote:
    >Hi Todd,
    >
    >I haven't done this, but the LOSA mentions someone using the RESET pin as a
    >form of interrupt. I haven't looked at it, but this would likely require a
    >differentiator (in other words, a capacitor so you just get a pulse on the
    >reset) and a latch connected to an input pin.
    >
    >On reset, you look at the latch. If it is 0, you just got reset. If it is 1,
    >you just got interrupted. Of course, you can't return from the interrupt in
    >any real sense. But you can service an external event and the go on with
    >what you normally do. The LOSA is at -- I think -- www.hth.com/losa.
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