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Altera_Forum's avatar
Altera_Forum
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13 years ago

How to prevent QII inferring RAM

Hi there, I have an array of registers that are 32 bit wide and need to be accessed in a different clock domain. So I wrote a process to cross those registers to the new clock domain by double-...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
13 years ago

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Doubling registering arrays will work to cross the boundary, but a FIFO would be more reliable.

You'll probably fnd quartus isnt infering a RAM, its infering an ALTSHIFTTAPS megafunction, which will use RAM, because all you have is a shift register.

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Yeah, it was a memory block in the Altshifttaps megafunction (stratix iv) and it gave timing violations. I will use fifos instead.

Thanks!