FPGA, SoC, And CPLD Boards And Kits
FPGA Evaluation and Development Kits
5892 Discussions

About Arria V LVDS output

JLIU45
Novice
1,190 Views

I'm uising arria V device in my project, a pair of LVDS pins are used in my design, which are configured as output. It always cannot work well, and by using OSC I watched the output waveform of LVDS port, it was quite strange, the pos and neg pins are the same, and even the Vocm and Vdm is incorrect, refer the below image. I'm sure the pin configuration is accurate, and the pins is not demaged since I tried another LVDS pin. So, whats could be the reason? thanks

0 Kudos
10 Replies
SreekumarR_G_Intel
1,122 Views

Can you share the sch and output interface connected to the LVDS output ?

 

Thanks ,

Sree

0 Kudos
JLIU45
Novice
1,122 Views

Yes, pls see the attached images. In fact I use Arria V GX Starter Kit Board as LVDS transmitter, and C5 board is our own, there is no other devices on the LVDS bus, just connecting the Arria V to Cyclone V direclty.

0 Kudos
JLIU45
Novice
1,122 Views

my C5 board

0 Kudos
JLIU45
Novice
1,122 Views

Hi, is there any update?

0 Kudos
SreekumarR_G_Intel
1,122 Views

Hello,, sorry for delay in response.

There should be common mode voltage in the LVDS bus which i didnt see in the graph you sent me.

can you check the LVDS std is set correctly ?

 

Thank you,

 

Regards,

Sree

0 Kudos
JLIU45
Novice
1,122 Views
Hi, thanks. I just set the I/O standard to LVDS in pin planner, always I do like this, and it works well besides this case. For Arria-V device, is there any other special configuration for LVDS pin?
0 Kudos
JLIU45
Novice
1,122 Views

Hi, how is the thing going on? thanks

0 Kudos
SreekumarR_G_Intel
1,122 Views

Sorry , I am not sure what is missing here.

Can you check is IO is not open ended ? Pretty much looks like other side is open.

Is there any external termination ?

 

Thank you ,

 

regards,

Sree

0 Kudos
JLIU45
Novice
1,122 Views
Hi, The LVDS output is connected to another LVDS input directly, and there is termination on the receiver side. Also, I’ve mentioned I compared the LVDS output between Arria V and cyclone V, for both the LVDS output is open, the waveform is quite different.
0 Kudos
YuanLi_S_Intel
Employee
849 Views

This thread will be transitioned to community support. If your question is not addressed yet or you have a new question, feel free to open a new thread to get the support from Intel experts. Otherwise, the community users will continue to help you on this thread. Thank you

0 Kudos
Reply