Altera M4K memory usage

Apr 19, 2007 2 Replies
M

Hi everybody,



I'm using a Cyclone II EP2C20 which has 52 M4K memory blocks with each



4096+512bits. I want to use the whole memory, but I can't use the additional 512bits of the M4K blocks. if I make "a lpm_ram_dp" or "altsyncram" with 16384 8bit words the usage is:
20 lut + 32 M4K + 4 reg if I make "a lpm_ram_dp" or "altsyncram" with 16384 9bit words the usage is:
22 lut + 36 M4K + 4 reg the 9th bit (parity) is not in the additional 512bits of the M4K blocks but in 4 more M4K blocks!!!??? How can I use this additional 512bits of the M4K blocks??? Is there an other megafunction which uses this bits???

Thanks for any help, Manfred


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T

The "problem" is that Quartus by default uses the M4Ks in the 4k x 1 mode for such large memories (better performance). In the MegaWizard you can limit the maximum words per M4K to 512, Quartus will then use the 512x9 mode (this will need more LUTs for output-multiplexing and has less performance).

Regards,

Thomas

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"Manfred Balik" schrieb im Newsbeitrag news:46272a43$0$10578$ snipped-for-privacy@tunews.univie.ac.at...

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M

Thanks, I've tested it and that solves my problem :-)))

"Thomas Entner" schrieb im Newsbeitrag news:46272c28$0$2298$ snipped-for-privacy@newsreader01.highway.telekom.at...

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