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Altera_Forum
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12 years ago

M9K parity usgae

Folks,

Is there any way to use the whole 9Kbit of each M9K in Cyclone III? My observation shows that Quartus compiler tool utilizes M9K as 8kbits blocks of memory. I intend to use the extra space for parity.

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  • Altera_Forum's avatar
    Altera_Forum
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    12 years ago

    --- Quote Start ---

    Folks,

    Is there any way to use the whole 9Kbit of each M9K in Cyclone III? My observation shows that Quartus compiler tool utilizes M9K as 8kbits blocks of memory. I intend to use the extra space for parity.

    --- Quote End ---

    I don't know about cyclone but in general you can use parity bit for block depths of 1024 and below. This because the parity bits are addressable for such depth only.
  • Altera_Forum's avatar
    Altera_Forum
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    12 years ago

    The dword is actually 9 bits when set to 1k mode, or 18 bits for 2k mode. So you need to make sure the memory is used appropriatly. How are you using it? megawizard or inference?

  • Altera_Forum's avatar
    Altera_Forum
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    12 years ago

    I am using a Cyclone 3 device. for changing the size I just change it in teh file itself and not use of megawizard. Fitter report shows 421,304 memory bits of my device is used. The whole memory bits is 608256! I have plenty of room left, but Fitter complains that it needs 68 M9K and the device has 66 M9K. This is so ridiculous! Is there a way to optimze M9K usage?

    Based on the report of fitter Quartus tool does not use extra 1kbit of data of each M9K. That is why we are wasting lots of resources. I am curious if there is a way to use the whole bits of each M9K!
  • Altera_Forum's avatar
    Altera_Forum
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    12 years ago

    go to megawizard and set block size to 1024 or lower(this is not same as depth of your required ram but depth of each block) then read the ram required.