PRESERVE_UNUSED_XCVR_CHANNEL persisting critical warning

Hi Leon -

I don't think that OFF is a legitimate setting for this. It's off by default, so "set_instance_assignment -name PRESERVE_UNUSED_XCVR_CHANNEL OFF -to PIN_AC38" would have no effect.

I think the best way to handle this is to do a global enable:

set_instance_assignment -name PRESERVE_UNUSED_XCVR_CHANNEL ON

This will preserve all unused transceiver channels at the cost (supposedly) of only 1mW extra power dissipated per channel.

See this as well:

https://www.altera.com/support/support-resources/knowledge-base/solutions/rd06092016_720.html

So to get the full effect you need to install update 1 to QP 16.0. This was news to me as well. Altera has done a terrible job of explaining this whole unused transceiver BTI degradation issue. It's not mentioned anywhere in the Arria 10 documentation. I discovered it when I saw lines like this in the .qsf files for Arria 10 reference designs from rocketboards:

set_instance_assignment -name ENABLE_UNUSED_RX_CLOCK_WORKAROUND ON -to AE33

I asked our local Altera account manager about it and she forwarded me some info on it from a super-secret Altera internal presentation. Really stupefying to me the way they handle issues sometimes.

Now when I build with 16.0 I get the following fitter messages:

Warning (18687): The QSF assignment ENABLE_UNUSED_RX_CLOCK_WORKAROUND has been deprecated. It has been superseded by the QSF assignment PRESERVE_UNUSED_XCVR_CHANNEL.

Info (17952): Channel-specific preservation of unused RX channels is enabled. Preserving 10 unused RX channel location(s).

Info (17953): Preserved 10 unused RX channel(s).

So the ENABLE_UNUSED_RX_CLOCK_WORKAROUND setting has been replaced by PRESERVE_UNUSED_XCVR_CHANNEL in 16.0, but they forgot to preserve the unused Tx channels. To get that you need to update to 16.0.1.

Hard to keep up with all the secret half-information with Arria 10.

Good luck. I hope this helps.

Bob

I just installed 16.0.1 and included the following in the .qsf file:

set_instance_assignment -name PRESERVE_UNUSED_XCVR_CHANNEL ON

I now get the following messages from the fitter:

Info (17952): Global preservation of unused RX channels is enabled. Preserving 48 unused RX channel location(s).

Info (18653): Global preservation of unused TX channels is enabled. Preserving 48 unused TX channel location(s).

Info (17953): Preserved 48 unused RX channel(s).

Info (18654): Preserved 48 unused TX channel(s).

This is targeting ES2 silicon on the Arria 10 SoC dev kit.

Bob

Hi Bob,

Great thanks for your help.

Do you use the Pro version of Quartus 16.0.1 ?

I tried the Standard version (16.0.1) and this PRESERVE_UNUSED_XCVR_CHANNEL seems to be ignored.

I'm installing the Pro version now and hopefully I will get the same Fitter Info messages as you saw

Leon

Hi Leon -

I'm using the standard version. Minor correction to my post above. I'm actually using this syntax:

set_global_assignment -name PRESERVE_UNUSED_XCVR_CHANNEL ON

Not sure if that will make a difference for you or not but maybe worth a try.

Bob

Hi Bob,

That made it working. (it should be "set_global_assignment" and not "set_instance_assignment".

Now I see in the Fitter log:

Info (17952): Global preservation of unused RX channels is enabled. Preserving 72 unused RX channel location(s).

Info (18653): Global preservation of unused TX channels is enabled. Preserving 72 unused TX channel location(s).

Info (17953): Preserved 72 unused RX channel(s).

Info (18654): Preserved 72 unused TX channel(s).

So, problem solved. Thanks!

Regards,

Leon

BTW:

I'm still using Quartus 16.0.0 standard.

(I cannot get the pro version to work; I get the same issue as described here: http://www.alteraforum.com/forum/showthread.php?t=52337&highlight=prime )

Thanks Bob,

Your last message made it working. I corrected the syntax and in Quartus 16.0.1 (standard) it is working now.

Thanks for your help!

Leon

(hope my reply will get through this time..)