UPGRADE YOUR BROWSER

We have detected your current browser version is not the latest one. Xilinx.com uses the latest web technologies to bring you the best online experience possible. Please upgrade to a Xilinx.com supported browser:Chrome, Firefox, Internet Explorer 11, Safari. Thank you!

cancel
Showing results for 
Search instead for 
Did you mean: 
Observer paulcarson
Observer
229 Views
Registered: ‎04-22-2014

Differential SerDes input DIFF_TERM & Constraints implementation

Jump to solution

Hi folks,

On our Artix7 we have a CameraLink Receiver implemented using the ISERDES with Differential inputs from a DS90CR287 with external 100R terminations across the FPGA pins as we are using a VCCIO=3.3v. The pins are configured for LVDS_25.
We need to ensure the DIFF_TERM is disabled to avoid smoking the device.

Our clock inputs declared as:

CLK1_IBUFDS : IBUFGDS
generic map(
DIFF_TERM => FALSE,
IBUF_LOW_PWR => TRUE,
IOSTANDARD => "LVDS_25"
)
port map(
I => GL_CLK_1_p,
IB => GL_CLK_1_n,
O => GL_CLK_1
);

Can someone please confirm that as the DIFF_TERM for the IBUFGDS is declared in the VHDL, that it is not required in the XDC file?
Can someone please confirm that as the LVDS_25 for the IBUFGDS is declared in the VHDL, that it is not required in the XDC file?

The SelectIO wizard generated the CameraLink RX SERDES but there is no Generic declaration for these items.

Should we add DIFF_TERM = FALSE to our XDC file?
Should we add LVDS_25 to our XDC file?

We have searched the project folder and cannot find another XDC file with these settings implemented for the SERDES or IBUFGDS pins.

Best Regards,
Paul

 

0 Kudos
1 Solution

Accepted Solutions
Moderator
Moderator
198 Views
Registered: ‎08-08-2017

Re: Differential SerDes input DIFF_TERM & Constraints implementation

Jump to solution

Hi @paulcarson 

If you are setting DIFF_TERM and IOSTANDARD attribute in instatiation itself, there is no requirement to add constarints in XDC.

Capture.JPG

-------------------------------------------------------------------------------------------------------------------------------
Reply if you have any queries, give kudos and accept as solution
-------------------------------------------------------------------------------------------------------------------------------
1 Reply
Moderator
Moderator
199 Views
Registered: ‎08-08-2017

Re: Differential SerDes input DIFF_TERM & Constraints implementation

Jump to solution

Hi @paulcarson 

If you are setting DIFF_TERM and IOSTANDARD attribute in instatiation itself, there is no requirement to add constarints in XDC.

Capture.JPG

-------------------------------------------------------------------------------------------------------------------------------
Reply if you have any queries, give kudos and accept as solution
-------------------------------------------------------------------------------------------------------------------------------