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Valued Contributor III

SDRAM problems migrateing neek tutorial to 10.0


I have tried running SOPC builder on the neek_sopc_builder_hw_tutorial using the latest set of tools, quartus 10.1. I get the following error when I generate; 

Error: ddr_sdram: DDR and DDR2 SDRAM controllers in High Performance Controller II architecture only support "Memory burst length" setting of 8 at half rate. Click "Modify Parameters" in "Memory Settings" page to change the "Memory burst length" or change the controller data rate. 

Warning: ddr_sdram: Cannot meet tRRD requirement of 0.0 ns. For a Memory interface clock frequency of 150.0 MHz, the minimum is 7.3 ns. Click "Modify Parameters" to change the requirement or adjust the Memory interface clock frequency. 


Where am I going wrong and what has changed between 9.0 and 10.1 


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Valued Contributor III

Re: SDRAM problems migrateing neek tutorial to 10.0

I recommend doing this: 


1) Change the memory controller to HP2 version 

2) Change the memory device settings to a burst length of 8 (the modify parameters button) 

3) Change the local burst length to 1, this is new in the HP2 controller 


The HP2 controller is able to take sequential accesses and turn them into a burst which is the reason for step# 3 above. If you didn't make that change then the memory local side (slave port) would support a burst length of 2 by default which would require bursting masters to access it efficiently. Using a local burst length of 1 and using an arbitration share of 2 or greater should give you the same throughput only without having to worry about burst adapters and whatnot.
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