Field in PARK_PTR_REG register of VDMA uses Gray code or Binary Code?

[gdhorse]

Hello,

I am using VDMA for data transferring from PL to PS. For S2MM channel, the WrFrmStore field in PARK_PTR_REG indicates the current frame number that is operated by the IP. How this field is coded? Is it gray code like the s2mm_frame_ptr_out/s2mm_frame_ptr_in port? Or is it a simple binary code?

I don't find explict description about in the VDMA manual. I don't have chance to verify this in real hardware yet. I have also checked the source code of XAxiVdma_CurrFrameStore() function in VDMA standalone driver, and some posted topic in Xilinx forum. It seems the WrFrmStore is binary code. Can anyone confirm this or show me the document that mentioned this?

Regards,

Jun

Related topics I have read:

https://forums.xilinx.com/t5/Embedded-Development-Tools/AXI-VDMA-PARK-PTR-REG-always-returns-zero/m-p/568719#M34938

https://forums.xilinx.com/t5/Video/VDMA-ring-buffer-is-not-in-sequence/m-p/890262?advanced=false&collapse_discussion=true&filter=location&location=forum-board:DSPTOOL&q=PARK_PTR_REG&search_type=thread

[florentw · Accepted solution]

Hi @gdhorse ,

You can do the test quickly. You will see that this is only binary values.

In general if this is not mentioned, this means that this is not encoded (but you are never safe from editing errors).

Regards,

[florentw]

Hi @gdhorse 

Do you have any updates on this?

If your question is answered or your issue is solved, please kindly mark the response which helped as solution (click on "Accept as solution" button below the reply)

If this is not solved/answered, please reply in the topic giving more information on your current status.

Thanks and Regards,

[gdhorse]

Hi @florentw ,

I am really sorry for the late response... Yes, your answer solved my problem, and I have created a test project in a demo board and verified the PART_PTR_REG value. Thanks a lot!

BTW, could you please check if I have accepted this as solution? I don't see the button about it..

Regards,

Jun

[florentw]

Hi @gdhorse ,

Yes you accepted as solution. You can see that my reply is now marked solution:

and the name of the page is now starting with solved:

This can help other members to find solutions more easily.

Thanks,