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Altera_Forum
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12 years ago

Quartus sythesizes double the on-chip memory bits

Hello, I'm testing out how to code and simulate the on-chip memory usage, which is working well. However I've noticed in the Flow Summary window after compiling, it's using double the memory ...
Altera_Forum's avatar
Altera_Forum
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12 years ago

The behavior you are seeing is most likely the result of how the tools are optimizing away resources due to the fact that your supplied address is fixed value. For example, it doesn't know how to produce zero address lines, so you are stuck with one address line after synthesis, which the fitter knows can correspond to a depth of 2.

Make your 'address' come from an input port and you will find that the RAM summary will report a power-of-two 'depth' based on the width of the address.