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Altera_Forum
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16 years ago

Something about using ram in FPGA

Hi everybaby: When I use ram in FPGA greater than %75,Quartus show me that something wrong with it !It means ram is not enough! :confused: Thanks for somebaby who know how to do it!
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Altera_Forum
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16 years ago

As Daixiwen already mentioned, it is mostly impossible to use 100% of the internal ram.

As an example if you are using a cyclone II with M4K memory blocks. according to the device datasheet such a M4K has a total of 4608 bit you can implement a 512 x 8 memory out of such a single M4K but 512 x 8 is 4096 bit. in that case you have 4608 - 4096 = 512 bit unused and you can not use them for other puspose as this M4K block is used. so if you do not use all bits from your M4K memory blocks you can't reach 100%. for this example 4096 from 4608 bit means you have used only 87%..

if you want to know how much is realy used, look into the compilation report -> Fitter -> Resource Section -> resource usage summary. their you can see the truth, the compilation report -> flow summary what is displayed directly after the compilation is for sales guys ;-)