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Altera_Forum's avatar
Altera_Forum
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12 years ago

Multi SD CARD controller

Hi all,

I'm doing a design with 4 SD cards, in sd 4 bits mode at 50MHz in parallel with an embedded Nios on a ARRIA V target.

Here are the facts:

- By instantiating the sd ip without Nios, communication goes well and we arrive to write fixed pattern on all cards.

- By adding the Nios (Nios + RAM + Ethernet), there are 2 cards of 4 arriving to work properly

Has anyone ever used multiple SD cards within one design?

Are there timing constraints add on the sdc file to use efficiently sd card ?

I suspected problem of random delay depending on the quartus routing or fitting, between the sd clock and the 4 bits of data.

Thank you for your help

5 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    12 years ago

    How have you constrained this?

    Yes, you will have to ensure you clock to out times are appropriate. However, you mention running at 50MHz - I don' think you should have much of a problem in Arria running at that frequency.

    Are you registering data on and off the FPGA in the I/O cell?

    Are you happy that, in connecting up your Nios core, you haven't inadvertently incorrectly connected something?

    Regards,

    Alex
  • Altera_Forum's avatar
    Altera_Forum
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    12 years ago

    Hi Alex

    Thank you for responding,

    Yes, data are registered in the I/O cell.

    I'have checked, all connections are ok.

    Below the corresponding sdc file lines and attached the sd specification, could you check if it is correct?

    #create 50 mhz clock

    create_clock -period 20 -name {c0_sd_clk} [get_ports {c0_sd_clk}]

    # constraint of sd output delay time (fpga input)

    set_input_delay -clock { c0_sd_clk } -add_delay 14 [get_ports {c0_sd_dat* c0_sd_cmd}]

    # constraint of sd output hold time (fpga input)

    set_input_delay -clock c0_sd_clk -min -rise 2.5 [get_ports c0_sd_dat* c0_sd_cmd]

    # constraint of sd input setup time (fpga output)

    set_output_delay -clock c0_sd_clk -max -rise 6 [get_ports c0_sd_dat* c0_sd_cmd]

    # constraint of sd input hold time (fpga output)

    set_output_delay -clock c0_sd_clk -min -rise 2 [get_ports c0_sd_dat* c0_sd_cmd]

    Regards,

    Hery
  • Altera_Forum's avatar
    Altera_Forum
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    12 years ago

    Are you still having problems with this?

    I don't see anything wrong with the set of constraints you've posted. Can I assume you used this same set of constraints successfully in your non-Nios version?

    My suspicion her is still with a higher level functional issue.

    Regards,

    Alex
  • Altera_Forum's avatar
    Altera_Forum
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    12 years ago

    Hi Alex,

    Thanks for your help.

    Timing constraints and data synchronisations were failed.

    Regards,

    Hery