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Altera_Forum
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16 years ago

DDR SDRA IP local address

I try to use DDR SDRAM IP controller. I need it for 1 Gbyte DDR memory. after setting the block and the controller sign that we have 1 Gbyet memory we only get 26 address line, and we need 27 ad...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
16 years ago

Ok, for a x128 local side data path 26 bits sounds right.

log2(1024*1024*1024 Bytes/16 Bytes per word) = 26

I'm not sure what an address bit 0 stack is so I can't really comment further about that. If you were to ground out one of the address bits that will get you to 25 connected address lines however that will limit you to only using half the memory available on the DIMM. Others sometimes use something called a "window" bridge where you control how much address space of the memory you want to be able to access at any given time.