Arty Z7 HDMI out demo: no output

[lvoudour]

Hello,

I just got the Arty Z7 and I was trying the HDMI out demo. I followed the SDK handoff guide, downloaded the bitstream and run the demo. I can see the serial output and can enter commands,

but I get a "no signal" on my monitor no matter the resolution. Checked and rechecked the connectors to no avail. I tested my monitor's HDMI input with the same cable on a raspberry pi and it works fine.

I'm running Vivado/SDK 2016.4 on Xubuntu 17.1

Any ideas?

 

Question 2:

Is 1080p output really in spec for Z7? The zynq datasheet shows 950Mbps as the max for LVDS OSERDES

Thanks

[lvoudour]

*UPDATE*

Going the "vivado way" (create project, generate bitstream, export hardware and launch SDK) it works great!

It still bugs me why the SDK way doesn't work (tried it again afterwards still no luck). Maybe one of your engineers can take a look at it?

For those in ubuntu linux take note that I run to all sorts of problems until I could successfully run the create_project.tcl in vivado, mainly missing libraries. In the end I had to comment the last lines in the script

# if {[llength $sdk_list] != 0} {
# 	 exec xsct -eval "setws -switch ../sdk; importproject ../sdk"
# }

because xsct caused vivado to hang. If anyone has any questions (or any solution to the last part) please tell me

By the way, I tried it in windows 10 as well but I have vivado 2017.3 installed and I gave up because I couldn't build the application. Steps I followed:

• Downloaded the latest digilent vivado libraries
• Updated xilinx ip cores
• Recreated the hdl wrapper
• Fixed the location of some pins that for some reason were incorrectly assigned
• Regenerated the fsbl and the demo bsp
• Tried different toolchains (arm gnu v7 and v8) because it couldn't find the default one
• Got ld errors I couldn't resolve and just gave up

Anyway, I'll stick to 2016.4 which seems to work for now

Question 2 still stands: Is 1080p in spec? If not, shouldn't there be a note in the project wiki?

Thanks

[Lao.Alex.512]

1080p should be out of spec, the OSERDES runs at about 1500 Mbps if regular timings are used. You should see the timing failure in the implementation timing report. 

[sbobrowicz]

Yes, 1080p is out of spec for the serdes and some of the clocking infrastructure. We include it in the project because in our experience 1080p will work on the output side most of the time (I personally have not had any issues with it across many different boards and monitors). We can add a note to the wiki for the project

[jpeyron]

Hi @lvoudour,

We plan to resolve any of these issues with Vivado and SDK when we update the project to 2017.4. 

thank you,

Jon

[lvoudour]

On 12/17/2017 at 8:26 PM, Lao.Alex.512 said:

1080p should be out of spec, the OSERDES runs at about 1500 Mbps if regular timings are used. You should see the timing failure in the implementation timing report. 

 

On 12/18/2017 at 9:44 PM, sbobrowicz said:

Yes, 1080p is out of spec for the serdes and some of the clocking infrastructure. We include it in the project because in our experience 1080p will work on the output side most of the time (I personally have not had any issues with it across many different boards and monitors). We can add a note to the wiki for the project

Thanks, it makes sense now. By the way which part of the clocking infrastructure does it violate? I'm doing a manual dvi implementation right now and I'm pretty sure I can generate a ~750 MHz ddr clock without violating the MMCM vco Fmin/max limits (unless I'm reading something wrong from the datasheet)

 

22 hours ago, jpeyron said:

Hi @lvoudour,

We plan to resolve any of these issues with Vivado and SDK when we update the project to 2017.4. 

thank you,

Jon

That's great. Thanks!

[Lao.Alex.512]

You will violate the clock buffer minimum pulse width requirement and the OSERDES DDR minimum pulse width requirement. 

[lvoudour]

On 12/20/2017 at 4:31 AM, Lao.Alex.512 said:

You will violate the clock buffer minimum pulse width requirement and the OSERDES DDR minimum pulse width requirement. 

Of course, you're right, thanks Alex