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Altera_Forum's avatar
Altera_Forum
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16 years ago

ALTMEMPHY without PLL

I created a DDR2 controller with Megawizard. My question is there a way to create it without PLL. I want to use a own PLL, since our design uses all PLL, and we would like to reuse one of the existin...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
16 years ago

The PLL is integral to operation. DDR2 is all about passing data between phase-shifted clock domains and what-not. Maybe you can create the clocks you need from the DDR2 PLL? You can go into the PLL inside the DDR2 and modify it, such as adding another output. (The Cyclone III PLLs don't have a ton of outputs, so I'm not sure what's possible. I've done this on Stratix DDR2 designs before.)