About PRESERVE_UNUSED_XCVR_CHANNELfor transceiver application

Hi dlim,

If I use 18.0.0,

1) for the unused tx and Rx channel, I use the preserve command

set_global_assignment -name PRESERVE_UNUSED_XCVR_CHANNEL ON, but this command will lead to the risk presented in the link2.

so the best method is that I use the set_instance_assignment -name PRESERVE_UNUSED_XCVR_CHANNEL ON -to <pin_name>

Q1 : If so, I want to know the way to use this command:

for example : for differential pins, rx0p(k20), rx0n(k21)

so for these two pins, I need to write the assignments which has two methods:

case one:

1) set_instance_assignment -name PRESERVE_UNUSED_XCVR_CHANNEL ON -to k20

2) set_instance_assignment -name PRESERVE_UNUSED_XCVR_CHANNEL ON -to k21

case two:

I only need to write one as 1).

I want to know which one is right?

Q2 : I want to know which pins I need to assignment ? All unused pins? If so, when I do this， I face the fitter error. If not, which unused pins I need to assign, could you provide some advice?

Error :

Error (175019) : Illegal constraint of HSSI_PMA_TX_BUF to the location HSSIPMATXBUF_1C5

Info (175028) : The HSSI_PMA_TX_BUF name(s) : UNUSED_RXTX_CLOCK_WORKAROUND_FITTER_INSERTED_PMA_TX_BUF1

Error (16234) : No legal location could be found out 1 considered location(s). Reasons why each location could not be used are summarized below :

Error (175003) : The HSSI_PMA_TX_BUF location is occupied (1 location affected)

Info (175029) : HSSIPMATXBUF_1C5, Already placed at this location : HSSI_PMA_TX_BUF UNUSED_RXTX_CLOCK_WORKAROUND_FITTER_INSERTED_PMA_TX_BUF0

Brs,

Lambert

Hi,

You mean that I should not use any of the below assignment on quartus 18.0.0:

set_global_assignment -name PERSERVE_UNUSED_XCVR_CHANNELON

and

set_global_assignment -name PERSERVE_UNUSED_XCVR_CHANNEL <PIN_NAME>

right?

And what's the workaround, I didn't find it, could you please provide more detail information?

Brs,

Lambert

Hi Deshi,

Glad to your response.

But from the later compilation result, I found the problem can not resolve by the above assignment. Just because when I clear all the compilation content and add some new modules into my project, the transceiver works bad for one lane of one link( I have two links, each link @1 simplex Rx IP, four channel for each IP which use bonding mode) using new got pof file, and this case will not change no matter how many times I compiled using 18.0.

1) Compared to 18.0, if I use the same project (add some new modules), the transceiver work well using the pof compiled by 16.0 ( I didn't add any above assignment).

2) And I found that after compilation, if some logic unrelated to transceiver path in my project has timing slack problem, the transceiver can works well.

So, I think

1) maybe there's risk logic in my code, I can not make sure because some compilation result can work well.

2) maybe there's route and fitter problem, but from the report, I could't got any useful information for me to found them just because there is no warning information about transceiver and related transceiver logic has no timing issue. Could you provide me some advice for me to get more information about it?

For the transceiver, I only use its PMA part and fewer PCS part (enhance PCS, more PCS logic is writen by myself). And I check the lane error at the point closely to the IP OUT(parallerl data) (8B/10B decoder, M-PHY protocol, 10Gbps).

Brs,

Lambert

Hi Deshi,

Because that if I want to use newest software, I need to apply for software installation.

Continue to above problem,

I found that the routing hotspots is different for the pof file got from V16.0 and V18.0, as follow two pictures :

v18.0

V16.0

From above two picture, the routing hotspots got from V16.0 is better compared to the one got V18.0 (many part exceeds 95%), I compared the advanced settings of these two version software:

For synthesis:

For V16.0, it has "Synthesis migration checks for stratix 10 " and V18.0 has no this item;

For V18.0, it has "Allow Register Dupilation" and "Allow Register Merging" and V16.0 does not see these item (maybe it enable these defaultly)

For advanced fitter,

For V16.0, it has " i/o placement optimization" and " Spectra-Q physical Synthesis" and V18.0 has no these item;

For V18.0, it has " Allow register Dupilation" and "Allow Register Merging" and V16.0 has no these item(maybe it enable these defaultly).

Besides above difference, other item is same for V16.0 and V18.0.

So, For V18.0, I closed the "Allow register Dupilation" and "Allow Register Mergin" Item, but the routing hotspots change more worse.

Could you tell me the difference for the complication between V16.0 and V18.0, and is there solution for that I can got the routing hotspots (got V18.0) same as V16.0?

Brs,

Lambert

Hi Deshi,

Thanks for your help.

Brs,

Lambert