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Altera_Forum's avatar
Altera_Forum
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11 years ago

UniPHY DDR3 simulation is slow

I am using Modelsim to simulate a simple UniPHY DDR3 design and it takes ~10 minutes to finish the DDR3 calibration and assert the local_init_done signal. I did enable the Skip Calibration option in...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
11 years ago

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I am not seeing this or similar messages in the Modelsim transcript. My project is very basic. It contains one instance of the DDR3 IP and I am trying to do a simple write followed by a read. What performance should I expect with the Starter edition of Modelsim?

According to this article at http://www.altera.com/literature/hb/external-memory/emi_debug.pdf, full calibration should take 10 minutes and Skip calibration should take 3 minutes. Since my simulation time is right around 10 minutes, I am suspecting that I am doing a full calibration for some reason. Is there a way to check if calibration is really skipped?

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Examine "calib_skip_steps" (e.g. "sim:/x_ddr3_tb/x_ddr3_inst/mem_if_ddr3_emif_0/p0/calib_skip_steps"); I believe it ought to be all 1's if you are actually skipping everything.

In my simulation, 'local_init_done' goes high around 126us and takes maybe 2 minutes to get there, even with the project size warning I posted previously.