LVDS pin assignments

[msh]

Hi, 

I am trying to implement LVDS output in zynq 7020. 

In the IO bank 35 , I tried to to use a PIN as LVDS but there is always an error, as from the same bank there is another pin been used for default config with 3.3 voltage of VCCO .

[DRC 23-20] Rule violation (BIVC-1) Bank IO standard Vcc - Conflicting Vcc voltages in bank 35. For example, the following two ports in this bank have conflicting VCCOs:
START_PULSE_I (LVCMOS33, requiring VCCO=3.300) and StopSignal_P[0] (LVDS_25, requiring VCCO=2.500)

I read the below link 

https://www.xilinx.com/support/answers/64450.html

but it also didnt remove the error. 

Do I have to do some extra ? 

Please let me know how can I proceed

thanks 

[ashishd]

Hello @msh,

There are certain rules which needs to be followed while combining IOSTANDARDS in same bank. Please check page #97 from below UG

https://www.xilinx.com/support/documentation/user_guides/ug471_7Series_SelectIO.pdf

[msh]

Hello @ashishd

Thank you for me directing to the reference. 

According to the combination list, the output or input of different standard can be combine only if they have same VCCO. 

so does that mean I should use another IO bank for LVDS ? or there any other way ? 

Thank you 

[ashishd]

Hello @msh,

Differential inputs for LVDS_25 can be placed in banks with VCCO levels that are different from the required level for outputs. But you need to consider important criteria mentioned in Note 1 (page #100 ) from UG mentioned in my earlier reply. If this criteria is not followed, then you should consider using another bank.

[gnarahar · Accepted solution]

@msh As Ashish mentioned, LVDS outputs require VCCO to be at the respective Voltage level i.e. 1.8V for LVDS (HP Bank) and 2.5V for LVDS_25. 

LVDS Inputs though can be placed in bank with VCCO not matching to the required level with some conditions. 

Go through this AR which will pretty much explain the scenarios https://www.xilinx.com/support/answers/43989.html

In your case, you need to move LVDS_25 outputs to another Bank with 2.5V VCCO