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hydra crystal speeds — Parallax Forums

hydra crystal speeds

BadgerBadger Posts: 184
edited 2008-09-06 20:46 in Propeller 1
Hello

Just got a hydra kit. Was wondering what is the highest speed crystal it will take . It came with a 10 .

Badger

Comments

  • Mike GreenMike Green Posts: 23,101
    edited 2008-09-06 20:07
    The Propeller is designed for use of a 4MHz to 8MHz crystal. It has been used with a 10MHz crystal for the Hydra and the Spin Stamp. In that case, it's limited to a PLL 8x multiplier. The Propeller is specified for a system clock up to 80MHz. It generally works with system clocks up to 96MHz, but won't work reliably at that speed over the full military temperature range or over the full operating voltage range. There's some variation from chip to chip and batch to batch in terms of how much leeway there is. If you're building a product for someone, stick to the specifications. If you're tinkering, feel free to exceed them, but don't expect reliable operation and don't complain to Parallax.

    Post Edited (Mike Green) : 9/6/2008 8:12:49 PM GMT
  • BadgerBadger Posts: 184
    edited 2008-09-06 20:14
    Mike Green

    Thanks .. as to my surprise this hydra was donated to me through friends and family. They somehow found out I wanted one so they got it for me. I did not buy this item. just wanted that knew. But what you said about eh pll makes since i was using some of the test programs that came with it and some would not work at all. I think they were using a multiplier that was for a slower crystal. So i was over clocking it with out being in the know. Thanks for the info. The surgery went ok but the recoup has not been a good time. cant breath though my nose and that bothers me big time. have to sleep at a 45 degree with my nose taped up in gauss. Not a pretty site LOL

    anyway thanks for the info.

    Badger
  • Paul BakerPaul Baker Posts: 6,351
    edited 2008-09-06 20:31
    Badger, you're correct most of the demo code you'll see floating around was written for Propellers using a 5MHz crystal. Simply change the PLL16x in _clkmode to PLL8x (and _xinfreq to 10_000_000 if defined) and everything should work for you.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Paul Baker
    Propeller Applications Engineer

    Parallax, Inc.

    Post Edited (Paul Baker (Parallax)) : 9/6/2008 8:39:21 PM GMT
  • BadgerBadger Posts: 184
    edited 2008-09-06 20:46
    Mike

    as i thought

    thanks again for the info. I will look and make the changes. and Play with them again

    Badger
    Phil
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