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J
jm
Visitor II
July 25, 2003
Question

External RAM 8 bits 64K Mux

  • July 25, 2003
  • 2 replies
  • 639 views
Posted on July 25, 2003 at 09:26

External RAM 8 bits 64K Mux

    This topic has been closed for replies.

    2 replies

    J
    jmAuthor
    Visitor II
    July 25, 2003
    Posted on July 25, 2003 at 08:58

    Hi,

    I don t understand something about external bus controler:

    After configure correctly SALSEL=01 & CSSEL=01 register and BTYP=0; I use successful external RAM

    But

    when I want to use it in Mux mode (latch on POL), I change BTYP(=1) and it doesn t work. The signals seem good (CS1,RD,WR,Data&Adress) , but I can't neither write nor read the RAM (I verify data in Demux mode). After, I try to change wait state(0<=>15), no change......

    So, if you have a suggestion, I will be happy !!

    THANKS

    M
    maxime2399
    Visitor II
    July 25, 2003
    Posted on July 25, 2003 at 09:26

    Beside an erroneous connection, I think you should verify the bus timings,

    specially the timming related to the ALE/CS1 ALE/WR and ALE/RD.

    look at the timing on the memory side and see if it fits in its specification.

    If not, you may be able to update the configuration to make it work using the wait states, the tristate, changing the AEL length etc..
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