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K_Crocker's avatar
K_Crocker
Icon for Occasional Contributor rankOccasional Contributor
1 year ago
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LPM_MULT not working for Cyclone 10 GX device

I can't get a simple LPM_MULT instantiation to work. It simulates fine in Questa, synthesizes in Quartus Prime 24.2.0 Build 40 06/27/2024 SC Pro Edition without warnings, but 'result' is always 0 wit...
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  • K_Crocker's avatar
    K_Crocker
    1 year ago

    I could strip down the design, but I have some new information. I was able to work around the issue by changing the implementation style to "Use logic elements", in lieu of "Use the default implementation" or "Use the dedicated multiplier circuitry". I believe the default implementation is to use the dedicated multiplier circuitry. I think there really is a bug in the Altera LPM_MULT IP when using multiplier blocks.

    Changed to "Use loigc elements"Signal Tap showing ckt works as expected

K_Crocker's avatar
K_Crocker
Icon for Occasional Contributor rankOccasional Contributor
1 year ago

No. We've visited this issue before. The IP wizard instantiates lpm_mult. I've shown you the code it created. I don't see the point of doing this standalone. Perhaps you can tell me why a standalone instantiation would be any different from the IP wizard instantiation. The IP wizard creates a wrapper. I would just be removing the wrapper.