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Altera_Forum
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17 years ago

local_burstbegin on DDR2 HP

I'm debugging an issue where in simulation, my system can read/write to DDR2 via the DDR2 HP controller, however on a Stratix II GX chip, it cannot (specifically, the pci express dev kit). Look...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
17 years ago

local_burstbegin needs to be used no matter what the burst size. Look at the avalon spec :www.altera.com/literature/manual/mnl_avalon_spec.pdf

If the user guide says it only needs to be used for bl > 2 then it is wrong. burstbegin needs to be asserted for the first clock cycle of the xfer, and only for 1 clock cycle, even if the ready signal goes low at the start of an xfer. You need to make your interface look exactly the same as the spec says for it to work.

Kevin