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Altera_Forum's avatar
Altera_Forum
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10 years ago

ALTACCUM Megafunction not in Quartus II v 13.0.1

Hi there

I want to include an accumulator ino a design, but the ALTACCUM Megafunction seems to be missing. The ALTMULT_ACCUM is still present, but i don't want to waste the multiplier and add unnecessary latency. Is it possible to install the ALTACCUM Megafunction is some way. Has anyone else had this problem?

Regards,

stu84

3 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    10 years ago

    Which device family are you looking at? 'ALTACCUM' isn't supported beyond Cyclone III & Stratix III.

    Cheers,

    Alex
  • Altera_Forum's avatar
    Altera_Forum
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    10 years ago

    Hi there

    Thanks for the feedback. I am using a Cyclone IV, so ALTACCUM isn't supported I guess. Do you have any idea why? Is there a straight-forward alternative?

    Thanks again,

    stu84
  • Altera_Forum's avatar
    Altera_Forum
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    10 years ago

    I would simply code it into registers.

    ALTACCUM was, almost certainly, deemed superfluous with the number of registers and performance available in the newer families.

    What accumulator width and performance are you looking for? If your benchmark is the accumulator IP for Cyclone III then I suspect you'll achieve that in registers in Cyclone IV.

    Cheers,

    Alex