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GLCD KS0108 Dummy read. When? Once?

Discussion in 'Microcontrollers' started by atferrari, Aug 22, 2009.

  1. atferrari

    atferrari Well-Known Member

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    The datsheet of the KS0108 mentions the need of a dummy read whose results should be discarded.

    My questions:

    A) This dummy read is to be done:

    Just the first time I read RAM data, after a reset?

    Every time I want to read data from RAM?

    The first time after reset and the first time after any write?

    B) What materializes the second reading? In other words: just bringing the E pin high and then low again, generates the second reading?

    Gracias for any help.
     
  2. Pommie

    Pommie Well-Known Member Most Helpful Member

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    The dummy read tells the controller to fetch the actual data and make it available for the next read. The data fetch takes time and so you should check the busy flag before doing the next read. You only need a dummy read at the start of a read sequence.

    I posted example code here.

    Mike.
     
  3. atferrari

    atferrari Well-Known Member

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    Assembler only.

    Thanks Pommie.

    It is a pity but I work in Assembler only.
     
  4. dave

    Dave New Member

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  5. bryan

    bryan Member

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    Richard.C worked a lot on the KS0108 in asm to help me. I have some sample asm code that we eventually finshed that you are welcome to.
     
  6. atferrari

    atferrari Well-Known Member

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    If that means that I have the chance to have a look, good. Could you post it?
    Gracias for that.

    /Edit
    Hola Bryan,

    I found some code but it is for a display with serial inerface. I made a copy to give a look at it later.

    Gracias.

    /Edit
     
    Last edited: Aug 26, 2009

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