placement of GPIO with ALTLVDS LVDS pins on same bank failed

[kikoss]

Hello 

- I am using  Agilex7 , and I implemented the following LVDS design recommended by altera spec to place ALTLVDS and ALTLVDS RX on the same bank - (the bank used is 2F ) 

The design  compiles and fit well on the FPGA ,  and the IO standard used for the LVDS RX and TX is : I/O standard True Differential Signaling

- next step I did , is to add some single ended GPIO for external control 

I need the GPIO be on the same bank (2F) as the ALTLVDS RX and ALTLVDS TX pins 

But the placement failed and this is the error message 

Error(11924): Bank '2F' has conflicting VCCIO settings
Error(11928): 'TX_LVDS_ADC_4P~pad' with I/O standard True Differential Signaling, was constrained to be within bank '2F'
Info(11929): '1.5V' is a valid VCCIO value
Error(11928): 'GPIO1~pad' with I/O standard 1.2 V, was constrained to be within bank '2F'
Info(11929): '1.2V' is a valid VCCIO value

Seems some mismatch on the IO standard ... 

Is there some way to place GPIO and ALTLVDS lanes correctly  on the same bank ?  

THX 

Kikoss

[kikoss]

@FvM   
you may help about that .. 

THX

[FvM]

Hi,

thanks fo your confidence. Unfortunately I'm not yet familiar with Agilex FPGA series. 

As far as I understand Agilex 7 datasheet, true differential TX on GPIO banks requires VCCIO of 1.5 V, there's apparently no fitting single ended IO standard that could be used on an 1.5 V GPIO bank. What are your voltage requirements for single ended GPIO pin? 

[kikoss]

I have no special requirement for the GPIO since it connected to a custom board that we develop and we can adjust the voltage following the FPGA possibilities 

• I tried to set the GPIO to be 1.5V but the fiitter failed (this is my qsf command : set_instance_assignment -name IO_STANDARD "1.5 V" -to GPIO1 -entity safety_top_level)

• It failed also when I tried also to make the bank 1.5V as the following : set_global_assignment -name IOBANK_VCCIO 1.5V -section_id 2F

the error from the fitter is the same in the 2 cases
Error(12341): The output pin GPIO1 has a 1.5 V I/O standard, but the selected device does not support output pin operation with a 1.5 V I/O standard.

THX

[AqidAyman_Intel · Accepted solution]

Hello,

Unfortunately, for Agilex 7 devices, you cannot use single ended I/O in the bank that are using 1.5V for bank VCCIO. For VCCIO_PIO=1.5V, we don't support a single ended buffer, you can only configure the I/O for True Differential Signaling (TDS).

For VCCIO_PIO=1.2V, you can mix TDS RX and single ended 1.2V LVCMOS, 1.2V SSTL, etc in the same bank. We do not support TDS TX when VCCIO_PIO is 1.2V. 

Reference:

TDS specification: https://www.intel.com/content/www/us/en/docs/programmable/683301/current/differential-i-o-standards-specifications.html

Single Ended I/O specification:

https://www.intel.com/content/www/us/en/docs/programmable/683301/current/single-ended-i-o-standards-specifications.html

[kikoss]

Thank you very much both ! 

[AqidAyman_Intel]

No worries! I'm glad to help you.

May I confirm do you need more support on this?

[AqidAyman_Intel]

I hope the previous response was sufficient to help you proceed. As we do not receive any response from you on the previous reply have been provided, please login to ‘https://supporttickets.intel.com’, view details of the desire request, and post a feed/response within the next 15 days to allow me to continue to support you by replying to this thread.