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Frequency limitation for LAI in Arria 10

Seadog
Beginner
503 Views

I am planning to use the Logic Analyzer Interface to debug an Arria 10 design; documentation does not provide much in the way of performance specifications.

FPGA internal clock speed is ~300 MHz, meaning toggle rate of the I/Os would be ~150 MHz (I intend to use combinatorial/timing mode only).

Is this plan doomed to failure?

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3 Replies
sstrell
Honored Contributor III
115 Views

I think it really depends on the capabilities of your external logic analyzer. The LAI simply outputs internal signals to the I/O. Maybe you are thinking about Signal Tap, which does have a maximum supported frequency for sampling of the internal signals (used to be 200 MHz; may be higher for newer devices).

 

#iwork4intel

Seadog
Beginner
115 Views

Thanks for your response. I am not thinking of signaltap. LAI documentation does not specify a frequency limitation, though it does offer this:

 

"With the Signal Tap Logic Analyzer, you can acquire data at speeds of over 200 MHz. You can achieve the same acquisition speeds with an external logic analyzer; however, you must consider signal integrity issues."

 

If I build an I/O cell macro with the IP Parameter Editor, I get a message:

 

"Altera GPIO supports a maximum interface frequency of 300 MHz."

 

So that tells me that the GPIOs are good to 300 MHz; I assume this applies to 1.8V LVCMOS, which is what the LAI uses. The truth probably lies somewhere in between, but it is not clear what the I/O frequency limitation really means (does it mean I can't sample at 300 MHz, is 300 MHz the 3 dB point of the frequency response, etc.).

 

I don't expect PCB and connector SI to be a showstopper.

Rahul_S_Intel1
Employee
115 Views
Hi , There is a constrain when the frequency more than 250MHz , have to use termination. page no:183 https://www.intel.com/content/dam/www/programmable/us/en/pdfs/literature/hb/arria-10/a10_handbook.pd... Can you try to use the termination
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