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403 Views
Registered: ‎01-17-2018

GTX gen1 to gen3 switching

Hi Team,

I successfully completed PCIe Gen1 using GTX as RAW Serdes using "xc7k160tffg676-2" custom board. Thank you for your support.

 

Now i want to use GTX as RAW Serdes for both Gen1 and Gen3 also .

1. For that i need to switch GTX from Gen1 to Gen3

2. Previously I generated GTX ip core using cpll with rate 2.5 Gbps, now I generated 8.0Gbps.

My Controller will provide rate change signals

What I need to do for switching GTX from Gen1 to Gen3

 

Thank you

Krishna

 

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14 Replies
Xilinx Employee
Xilinx Employee
374 Views
Registered: ‎06-01-2017

Re: GTX gen1 to gen3 switching

You need to use DRP to write attributes to switch between these 2 designs. Assuming you have 2 designs built, one with Gen1 and one with Gen3. Use the attached script, run on an implemented design. It will dump all GT attributes to a gtParam.txt file. You can then use text compare software (or diff) to find out the attribute differences.

When you are ready to switch rates, apply the DRP writes, then assert reset_all.

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358 Views
Registered: ‎01-17-2018

Re: GTX gen1 to gen3 switching

Hi jhua,

Thank you for your valuable reply, but i didn't get any attached script here. I am using UG476 for GTX reference.
Can we write those attributes using registers?
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354 Views
Registered: ‎01-17-2018

Re: GTX gen1 to gen3 switching

and also can you please elaborate more on how to use scripts ?
1) at which stage should i source these scripts (after PNR or during running on hw with hw_manager)
2) will the scripts change the clk values and other attributes of the design or simply dump the gtx parameters file just for comparison purpose ?
3) Suppose if I am using DRP i/f , are these scripts still required ?
4) please also point which DRP ports i need to change for switching the rate .
5) please also let me know what are the parameters should i change b/w gen1 to gen3 and vice versa.
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Xilinx Employee
Xilinx Employee
339 Views
Registered: ‎08-07-2007

Re: GTX gen1 to gen3 switching

hi c.gannamani@gmail.com 

 

the script is just dumping the attributes for you to compare.

so that you can identify the attributes or ports that need to be changed.

 

Thanks,

Boris

 

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331 Views
Registered: ‎01-17-2018

Re: GTX gen1 to gen3 switching

Hi Boris,

Thanks for the Information, but i didn't get any attached script here. Please provide the scripts.

 

 

Thank you

Krishnachaitanya

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Xilinx Employee
Xilinx Employee
280 Views
Registered: ‎08-07-2007

Re: GTX gen1 to gen3 switching

hi c.gannamani@gmail.com 

 

you can find some useful tcl scripts here.

https://www.xilinx.com/support/answers/56137.html

 

the one you are looking for is gt_Attributes.tcl.

 

Thanks,

Boris

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269 Views
Registered: ‎01-17-2018

Re: GTX gen1 to gen3 switching

Hi,

Got the script file.

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262 Views
Registered: ‎01-17-2018

Re: GTX gen1 to gen3 switching

Hi,
I initiated the GTX ip core for 8.0 Gbps rate with qpll. When I tried to enable CPLL for Gen1 operation, unable to get the both TXOUTCLK and RXOUTCLK (also tx/rx usrclk's).My question is: Can I switch GTX from Gen1 to Gen3 by generating one instance of IP core.

+FYI,
My GTX generated Settings attached

gen3_gtx.PNG

gen3_gtx2.PNG

 

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Explorer
Explorer
247 Views
Registered: ‎04-06-2017

Re: GTX gen1 to gen3 switching

Hi, I am wondering how the 7 series transciever IP can be used to do PCIe communication. As far as I understand,7 series transciever IP does not include protocol. Do you mean you use to  7 series transciever IP as well as the protocol related module? 

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Xilinx Employee
Xilinx Employee
228 Views
Registered: ‎06-01-2017

Re: GTX gen1 to gen3 switching

Hi c.gannamani@gmail.com 

Are you able to operate with QPLL at 2.5Gbps?

If you attempted to switch from QPLL to CPLL when changing Gen3 -> Gen1, can you describe the list of attributes and ports you changed?

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216 Views
Registered: ‎01-17-2018

Re: GTX gen1 to gen3 switching

Hi greatmaverick,

I am using GTX transceiver wizard 3.6 as RAW serdes only, i am using our own controller and PIPE modules.

 

Thanks 

Krishnachaitanya

211 Views
Registered: ‎01-17-2018

Re: GTX gen1 to gen3 switching

Hi Jhua,
I am unable to operate with QPLL at 2.5Gbps.
Actually i want to establish Gen1 operation first and then Gen3, so I configured IP core for maximum data rate with QPLL.
I thought when i changed the tx/rx sysclksel[1:0] it will switch from QPLL to CPLL, But it is not changing(i checked in Simulation).
Is it possible to switch GTX from Gen1 to Gen3 by configuring IP core for maximum data rate with QPLL?
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Xilinx Employee
Xilinx Employee
197 Views
Registered: ‎08-07-2007

Re: GTX gen1 to gen3 switching

hi c.gannamani@gmail.com 

 

you need to generate two IPs by the transceiver wizard.

first is 2.5Gbps with CPLL, the other is 8Gbps with QPLL1.

compare the attributes & ports and identify diffs and switch between the two.

 

Thanks,

Boris

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Xilinx Employee
Xilinx Employee
195 Views
Registered: ‎08-07-2007

Re: GTX gen1 to gen3 switching

here is the baseline step

https://www.xilinx.com/support/answers/31968.html

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