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Does SHIFTIN/OUT 'Speed multiplyer' function? — Parallax Forums

Does SHIFTIN/OUT 'Speed multiplyer' function?

SteelSteel Posts: 313
edited 2007-02-26 23:54 in General Discussion
Just in testing a DAC with my SX28 and the SHIFTOUT COMMAND, I have changed the Speed Multiplier from 2 to 5000 .·

No matter what multiplier I choose, It takes the same amount of time to transfer data.

Are there any known bugs with the speed multiplier, or am I just seeing an anomolie?

Shaun

Comments

  • BeanBean Posts: 8,129
    edited 2007-02-26 20:49
    Shaun,
    At what speed are you clocking the SX ?

    Bean.

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    Cheap used 4-digit LED display with driver IC·www.hc4led.com

    Low power SD Data Logger www.sddatalogger.com
    SX-Video Display Modules www.sxvm.com
    ·
  • SteelSteel Posts: 313
    edited 2007-02-26 21:17
    50MHz external resonator.· (OSCHS1)
  • BeanBean Posts: 8,129
    edited 2007-02-26 21:39
    Hmmm, you should see some difference in speed then....
    Can you post your code ?

    Bean.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Cheap used 4-digit LED display with driver IC·www.hc4led.com

    Low power SD Data Logger www.sddatalogger.com
    SX-Video Display Modules www.sxvm.com
    ·
  • BeanBean Posts: 8,129
    edited 2007-02-26 23:54
    [noparse][[/noparse]Shaun sent his code via private e-mail]

    Shaun,
    · If you look at the generated assembly code you will see that the SHIFTIN if faster (the delay is controlled by __PARAM4) , but the other commands overshadow the speed increase.
    · I suspect the SERIN command after SHIFTIN is causing the hold-up.


    Bean.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Cheap used 4-digit LED display with driver IC·www.hc4led.com

    Low power SD Data Logger www.sddatalogger.com
    SX-Video Display Modules www.sxvm.com


    Post Edited (Bean (Hitt Consulting)) : 2/27/2007 12:01:13 AM GMT
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