Enabling OCT termination for Agilex5 Differential bi-drectional IOs

[PAA]

Hi, 

I am attempting to enable OCT termination for a bidirectional differential IOs for Agilex5. 

Due to the bidirectional nature, I can use only 'Differential 1.2v POD' or 'Differential 1.2v SSTL'. 
By default, these signals have dynamic OCT enabled, which is active when the data is received, and switched off (no termination), when the signals are outputting data. 
Both of these signals operate with a full swing of 1.2V with the n signal inverted to the p.  Thus the  differential output is seen to be 2.4V, which makes it out of specifications for the received.
As a work around I am trying to activate the Output OCT termination on these signals, but it seems to be failing. 
When I set the out put termination to simply 'parallel' the error message states that the termination is being set to 'off' and not acceptable for the differential signal standard of the receiver. 
When I set to 'Differential' or 'parallel termination 50 ohm' (calibrated or uncalibrated) , I get the message 'setting is not supported by I/O standard'

For example: 
Error(12418): Termination logic option is set to Differential for input pin tx_aux_diff_io|gpio_0|core|i_loop[0].altera_gpio_bit_i|input_buffer.ibuf, but setting is not supported by I/O standard Differential 1.2-V POD

Could someone clarify if I can set any / all of the following : 
1. Either disable 'dynamic' OCT termination for differential 1.2V SSTL or differential 1.2V POD to use external termination. 

2.Enable OCT for input as we as output for differential SSTL IO
3.Enable OCT for input as we as output for differential POD IO

The Altera document  813934 | 2024.04.05 (ug-813934-813935.pdf) does not clarify if Rt can or cannot be used when differential signals are in output mode.

[AqidAyman_Intel]

Hello,

Can you try to use Assignment Editor to configure the OCT?

Follow the steps from below link:

https://www.intel.com/content/www/us/en/docs/programmable/813934/24-1/configuring-oct-using-the-assignment-editor.html

Regards,

Aqid

[PAA]

Settings mentioned in my message are being applied in the Assignment editor itself! 

I am unable to disable the disable the OCT to use external termination. The settings seems to be applied correctly, but when we observer the signals on the oscilloscope, the Rx diff voltage is seen to be half of Tx, implying that the OCT is being switched on and off dynamically. 

[AqidAyman_Intel]

Thank you for the clarification. Can you help to share the example designs that demonstrate this issue?

It will help me to replicate so that I can investigate further this issue.