Setting up ZYNQ on Arty Z7-10 to write to the SD card on PL side

[Mahdi]

Hello,

I am trying to develop a simple verilog code on Arty-Z7-10 that writes to the SD card on the PL side, without having to use SDK software. To do so, I believe I need to setup my SD card pins as EMIO in the ZYNQ and modify the constraint file to uses correct pin mapping. However, I wonder if anyone has done such type of coding before and is able to provide me with more detailed information. I found this tutorial which has tried to do same thing with SPI, but it was not very detailed.

https://forums.xilinx.com/t5/Xcell-Daily-Blog-Archived/Adam-Taylor-s-MicroZed-Chronicles-Part193-The-Zynq-SoC-s-EMIO/ba-p/764971

I also found such SD card controller for Nexys4 board, while it seems a bit challenging to get it to work with Arty Z7 board due to different pin mappings.

https://web.mit.edu/6.111/www/f2015/tools/sd_controller.v

Any help is appreciated.

 

Thanks,

Mahdi

[jpeyron]

Hi @Mahdi,

I have not written to the sd card in hardware only with a ZYNQ processor. When I have some more bandwidth towards the end of next week I will attempt this kind of project.  In the  mean time I did find a forum thread that discusses adding a second SD card to a zynq processor here. I would also look as the reference manual under 7 microSD Slot as well.

thank you,

Jon

 

[Mahdi]

Hi @jpeyron

I have been looking at the references provided and had some success communicating with a PmodSD using a modified version of the code from the MIT website. However, I am having difficulty interfacing this code with the on-board SD card slot. What is confusing is that the SD input/output ports on the ZYNQ are split when exposed through EMIO. Do you have any recommendation on how to interface with the EMIO ports directly?

Thanks,

Mahdi

[jpeyron]

Hi @Mahdi,

I found a Xilinx forum thread that discusses this topic here.  Are you using the PmodSD for testing purposes? 

thank you,

Jon

[Mahdi]

Hi @jpeyron

I looked at the link you shared and if it is true what it says, I can only access the SD slot through SDIO controller when enabled through MIO. Does this mean that I can not control the SD card using a Verilog source code and I have to communicate with it only on PS side?

My question is exactly similar to the forum you shared. I am trying to access SD slot on-board of Arty-Z7 on the PL side, rather than PS side which is normally what people do. I used the PmodSD because I did not know how to get the on-board SD slot to work and PmodSD was for testing. At the end, my purpose is to write to the SD card mounted on the on-board SD slot in the PL side, but apparently nobody has an straight answer for that.

Best,

Mahdi 

[jpeyron]

Hi @Mahdi,

I'm sorry that my initial comment could be miss leading. Looking further into the topic the SD is tied to the PS .  You would not be able to directly interface to the SD card through the MIO pins.  I did find a thread suggesting it is possible indirectly here.  Are you trying to eliminate using the PS for efficiency?

thank you,

Jon