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DQ pins limitation of High Performance DDR2 Core

Altera_Forum
Honored Contributor II
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Hi, 

 

When I create a DDR2 Core of High Performance 8.0 which located on the top of the FPGA (StratixII EP2S30F672), and the data bus width is 32 (local bus width = 64, 4 dqs), error occured during Analysis & Synthesis. The Quartus II gave the message that the number of dq pins exceeded the maximum limitation of the DDR2 Core. 

Does it means I cannot implement a single High Performance DDR2 Core with 32 dq pins on one side of StratixII? 

In my design, I want to extend the data bus width from 16 to 32 using two 16bits DDR2 chip, and control the two DDR2 chip using only one High Performance Core. How can I achieve it? 

Another question: Does the High Performance Core always occupies 1 Enhanced PLL instead of Fast PLL? 

 

Thanks a lot!
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Altera_Forum
Honored Contributor II
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Perhaps it would be more beneficial if you actually posted the error that Quartus is giving you. The DDR2 core is certainly capable of handling a 32-bit interface. It may be that your device (EP2S30F672) doesn't have the capacity on one side of the chip. 

 

The DDR2 core requires a PLL. It can be either enhanced or fast I believe. 

 

Jake
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Altera_Forum
Honored Contributor II
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Which side of the chip are you trying to use? 

 

Jake
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Altera_Forum
Honored Contributor II
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Well I just did a test compile using the ddr2 example project. I was able to get the entire DDR2 interface onto one side of the chip (the bottom).

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Altera_Forum
Honored Contributor II
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Thank you! 

 

I want to instantiate the HP Core on the top of the FPGA device.  

The error I mentioned above is:  

Error: Delayctrlout port of DLL "ddr2:inst|ddr2_controller_phy:ddr2_controller_phy_inst|ddr2_phy:alt_mem_phy_inst|ddr2_phy_alt_mem_phy_sii:ddr2_phy_alt_mem_phy_sii_inst|ddr2_phy_alt_mem_phy_clk_reset_sii:clk|dll" feeds 4 DQS I/O pins that feed 32 DQ I/O pins. A maximum of 21 DQ I/O pins can be associated with single DLL. 

 

But, when I created another HP Core with the presets settings for Micron device (data bus = 72 and local bus = 144), the error above changed to "A maximum of 50 DQ I/O pins can be associated with single DLL." 

 

I am confused. If the maximum DQ I/O pins associated with single DLL is 50, why can't I instantiate a HP Core with 32 DQ I/O pins? 

 

Hope you to release me.:D :D
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