1GB RAM demands all available Addresses(SOPC Builder)

Question

Hey,

I use a Stratix III board with 1 GB of DDR2 Dimm(Micron MT9HTF12872AY-800E1 1GB(1152MB), DDR2, 800MHZ CL6). I use the DDR2 SDRAM HIGH Performance Controller. The SOPC builder tells me that it needs 2 gigs of addresspace(0x0 - 0x7FFFFFFF) So thats exactly 2 gigs of RAM and I only got 31 address bits(SOPC Builder tells me). So this demands all of my address memory. But I also use other MM-Slaves.

So what can I do? Why do I only have 31 address lines? One of my Avalon MM Slave devices also MUST be located at address 0x00. So the DDR2 Controller must be located at address 0x80000000 - 0xFFFFFFFF. Please help me. What can I do?

altera_forum · Answer

Problem solved. I just activated "Enable error detection and correction logic" so this seperates the ecc stuff to an owen port and so i just need a bit more then 1 gig of ram instead of 2 gigs :)

altera_forum · Answer

Adressbit 31 is used for cache bypass. so you only have bit 0 to 30 meaning 31 bit at all.

altera_forum · Answer

Where can I find "Enable error detection and correction logic" option?

altera_forum · Answer

SOPC Builder: click on options for the ddr2 SDRAM High Performance Controller and then click on the tab Controller Settings.

OK: It works that way:

Add the DDR2 SDRAM High Performance Controller. Do your settings at the Memory tab as well as at the PHY Settings Tab. Then click on the Controller Settings Tab and select "Enable error detection and correction logic".

The click on ok(So u use only 30 Bits for 1 Gig of Ram).

Then add a Avalon_MM Clock Crossing Bridge 2 times. Connect 1 to the S1-Port of the DDR2 Controller and the other to the ecc_slave port. The Addresses of the DDR2 Ram should start both at address 0x0(Otherwise you need more memory at the Clock Crossing Bridgets WITHOUT ANY advanteges!

I hope I wrote it clearly. At least my SOPC builder generates vhdl-code and i only need 0x4000400 memory addresses instead of 0x8000000.

altera_forum · Answer

oops !! it seems like I cannot use the DDR2 SDRAM High Performance Controller, since it is not supported in Cyclone II.

Anyway i solved the main problem by separating the addresses far away so it works now.

I am wondering if there is a way to use the DDR2 SDRAM High Performance Controller in Cyclone II!

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1GB RAM demands all available Addresses(SOPC Builder)

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