MicroBlaze tutorial (UG940) adapted to AC701 eval board

[kpados]

Hello,

I am following UG940 v2014.1 to get familiar with MicroBlaze. However, the evaluation board I have is an AC701, not the KC705 that the tutorial was originally written for. I have followed every step carefully, except for adding the "slave_banks" constraint that doesn't seem to apply 1:1 to the AC701.

The problem at hand is, when I get to step 11 (Executing the System) and I issue "connect mb mdm" in the XMD console, the JTAG chain is discovered successfully (also listing the CPU parameters and properties), but gives the following error message at the end:

ERROR: MicroBlaze is under RESET. Check if the Reset input to MicroBlaze and its Bus Interfaces are connected properly

UNABLE to STOP MicroBlaze

The reset on the board is high-active, which is consistent with the current setting of C_EXT_RESET_HIGH=1. Also, I tried executing the same command while I held the CPU_RESET switch of the board down which did not help, so I doubt the reset level is at fault here (at least not the reset level of the CPU).

Can you please provide some instructions to get the tutorial to work on the AC701 evaluation board?

Thank you

[htsvn]

Hi,

A quick check here would is to test the procedure outlined here.

http://www.xilinx.com/support/documentation/boards_and_kits/artix-7/ac701-bist-pdf-xtp194-2012.4-c.pdf

--Hem

[kpados]

Thanks Hem, I've tried the BIST example as you suggested, and it works. However, I would still like to know why the steps detailed in the MicroBlaze tutorial fail for the AC701, to gain more knowledge and learn.

[sampatd]

In step 11, instead of using the XMD console to program the fpga, can you try using Xilinx Tools> Program FPGA ?

Make sure that your bit file is updated with bootloop.elf

[htsvn]

Hi,

Thanks for confirming BIST works. So Board and it's interface are working as expected :)

Let us do the following:-

1. Go to SDK GUI --> Xilinx Tools --> Launch EDK shell

2. Copy the download.bit, application.elf into one location

3. Type xmd at the console.

4. Type the command "fpga -f download.bit"

5. Type "connect mb mdm"

6. Type "dow application.elf"

If this works, then we might have to look at the SDK settings used.

--Hem

[kpados]

Thank you guys very much for your kind help.

@htsvn: Unfortunately, these steps don't work either. "dow application.elf" fails because the "connect mb mdm" command did not succeed.

@sampatd: I tried that too, but the result is the same even if I use the GUI to download the bitstream.

For reference, I have attached the XMD log to this post.

[htsvn]

Hi

Quick thing to try, can you click on SW8(CPU reset) when trying to download the application?

--Hem

[kpados]

Tried, no difference. But XMD doesn't even try downloading the application because it is not connected to the FPGA, since the connect-command failed.

[michaelng · Accepted solution]

I was attempting to do the same thing (use UG940 for the AC701) and ran into the same problem. It appears that the MIG tool somehow sets the input clock to the wrong pins: N3/N2, which is designed to be a clock output to the DDR3. There will be nothing coming in on those pins, so the system never gets a clock and never comes out of reset.

The problem can be fixed by reconfiguring the MIG to use the correct clock input (SYSCLK on R3/P3). When I added clock ports and connected them, the tool complained, but it worked in the end.

[htsvn]

Hi,

That is a correct point. There is a known issue available here. (Xilinx Answer 60347) in the known issues of AC701.

The link seems to be broken. I will report this out to make it available

--Hem

[alexkarnaukhov]

Thanks you so much!

And is there is a way to get higher MB frequency with ac701 ?

Or 100 MHz is a limit there?

[_drakonoff]

Hi =)

How did you disabled clk_ref port in MIG IP? I cannot search this option)

Vivado 2018.3

Thank you and best regards!