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Altera_Forum's avatar
Altera_Forum
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16 years ago

C2 & C3 AS Mode EPCS without Altera EPCS IP

All Cyclone 1, 2 and 3 designs i have done with EPCS devices for AS configuration used the EPCS controller ip that is provided by the sopc builder with the nios cpu.

now i do a design that uses the epcs for configuration as well as for data that is fetched by the design to be used with other input data, but this time no nios is used instead pure hdl.

(a simple nios design will be used only to store the user image as well as the user data via jtag)

so i need to implement an ip that reads out the epcs with random read access, what is not a problem as these altera epcs (or from other manufactures) are well documented.

but i wonder if i would face difficulties.

within quartus device options under dual purpose options :

cyclone II devices

ASDO, nCSO only selectable as input tri-stated

but both are output of the fpga to the epcs inputs ADSI, nCS

so if they are only chooseable as inputs but my custom ip needs them as outputs ... that won't work :confused:

i am quite unshure if i misunderstood here something, also as the epcs ip is not fully documented by altera. does altera do something that is not made public to access the epcs devices in user mode ?

can somebody clarify that to me ?

5 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    16 years ago

    You should use the ALTASMI_PARALLEL megafunction described at http://www.altera.com/literature/ug/ug_altasmi_parallel.pdf

    Connection info and tips: http://www.alteraforum.com/forum/showthread.php?t=20967

    You can simulate it: http://www.alteraforum.com/forum/showthread.php?t=20899

    It works fine, but you should beware that Altera does not provide timing models. So help me out here: http://www.alteraforum.com/forum/showthread.php?t=20938

    (http://www.alteraforum.com/forum/showthread.php?t=20967)
  • Altera_Forum's avatar
    Altera_Forum
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    16 years ago

    --- Quote Start ---

    within quartus device options under dual purpose options :

    cyclone II devices

    ASDO, nCSO only selectable as input tri-stated

    but both are output of the fpga to the epcs inputs ADSI, nCS

    --- Quote End ---

    With Cyclone III, you can choose "Regular User I/O". For Cyclone II, this is not possible for some reason, but you can use the tornado_epcs_controller_atom (like Nios does). I think, this is undocumented, however. From my experience, you have to wait some micro-seconds, before the configuration-logic releases the EPCS and you can access it.

    So maybe ALTASMI_PARALLEL is the better solution (I have never used it).

    Thomas
  • Altera_Forum's avatar
    Altera_Forum
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    16 years ago

    There is a thread somewhere in the forum that tells that it also works for Cyclone II even though you can not select "Regular User I/O" for all ASMI pins.

    So yes, it also works for Cyclone II.

    Can you please add my rep power ? I heave more posts than you, but I have less :(
  • Altera_Forum's avatar
    Altera_Forum
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    16 years ago

    @ amilcar

    The rep power does not only depend upon the amount of posts, if you have a look at the joint date you will notice that tenter joint 2004 and you 2009 ... the rep power also depends upon the joint date

    maybe he posts "only" when he knows real good information and gets lots of reputations :-)

    @ tenter

    do have so more information about the tornado_epcs_controller_atom ?
  • Altera_Forum's avatar
    Altera_Forum
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    16 years ago

    All I know regarding the tornado_epcs_controller_atom, I know from looking to some files generated by the SOPC-builder. You can use it like this:

    module tornado_epcs_controller_atom (

    // inputs:

    dclkin,

    oe,

    scein,

    sdoin,

    // outputs:

    data0out

    );

    :

    :

    tornado_epcs_controller_atom the_tornado_epcs_controller_atom

    (

    .data0out (miso_of_spi),

    .dclkin (clk_of_spi),

    .oe (1'b0),

    .scein (cs_of_spi),

    .sdoin (mosi_of_spi)

    );

    Again, take care to not access to flash too early after configuration... (At least one Cyclone-family was a little bit critical there...)

    And regarding the reptuation power:

    - It indeed appears to depend on the join-date.

    - And I think, reputation-power and reputation should not be mixed up;)