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Altera_Forum
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8 years ago

Why is Hardware Multiplier removed in the Gen2 nios?

I've just got chance to work with NIOSII/QSYS after a long time.

In the classic NIOSII, there are 3 flavors. I was able to use hardware multiplier in the free NIOS core.

Now in the new generation, the free economy flavor doesn't support hardware multiplication anymore. How annoying.

What makes Altera remove the hardware multiplier support? or I'm missing something?

Jeff

4 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    Commercial reasons. A number of IP blocks, that used to be included with the free edition of Quartus, seem to have migrated to the subscription versions over the past few releases.

    You could always stick with an older release of Quartus...

    Cheers,

    Alex
  • Altera_Forum's avatar
    Altera_Forum
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    Thanks for replying. That kind of confirms my doubt.

    --- Quote Start ---

    A number of IP blocks, that used to be included with the free edition of Quartus, seem to have migrated to the subscription versions over the past few releases.

    --- Quote End ---

    That trend is odd, it should be the other way around.

    I can understand CACHE, MMU IP is "expensive" ... etc but Hard multiplier is just costless. Just another multiplexer port in the ALU.

    Altera, please support Hard Multiplier for the free NIOS :)
  • Altera_Forum's avatar
    Altera_Forum
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    As far as I'm aware the /e core has never actually included a hardware multiplier.

    Looking at the processor manual for 13.1 it says:

    Altera designed the Nios II/e core with a singular design goal: reduce resource utilization any way possible...Hardware resources are conserved at the expense of execution performance.

    The Nios II/e core employs dedicated shift circuitry to perform shift and rotate operations.

    The table on page 128 shows the features of the three types of core for the ALU where it says

    Feature.................../e core .../s core....../fcore

    Hardware Divide ........–.......Optional......Optional

    It was possible to select the implementation of the multiplier in the /s and /f cores but not the /e core which has no hardware multiplier....
  • Altera_Forum's avatar
    Altera_Forum
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    --- Quote Start ---

    As far as I'm aware the /e core has never actually included a hardware multiplier.

    Looking at the processor manual for 13.1 it says:

    Altera designed the Nios II/e core with a singular design goal: reduce resource utilization any way possible...Hardware resources are conserved at the expense of execution performance.

    The Nios II/e core employs dedicated shift circuitry to perform shift and rotate operations.

    The table on page 128 shows the features of the three types of core for the ALU where it says

    Feature.................../e core .../s core....../fcore

    Hardware Divide ........–.......Optional......Optional

    It was possible to select the implementation of the multiplier in the /s and /f cores but not the /e core which has no hardware multiplier....

    --- Quote End ---

    Thanks. My bad. I remember not using the FULL one. But the economy one is actually not supported.