Multi SD CARD controller

[Altera_Forum]

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

[Altera_Forum]

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]

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]

the SD SPECs bus timing paragraph

[Altera_Forum]

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]

Hi Alex, 

 Thanks for your help. Timing constraints and data synchronisations were failed.  Regards, Hery