MegaFunc. DDR2 High performance Controler issue

I am really confused. CT6464A667 should have the same timing parameter as CT12864AC667, why doesn't CT12864AC667 work, but CT6464AC667 works.

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hi everybody,

I am using example driver generated by mega wizard and altera ddr2 controller(with phy, No-AFI interface) as example to do a test. memory clock speed is 200MHz. I met with a very strange issue: the generated SOF can't work with Crucial DDR2 SODIMM, CT12864AC667, which is 64 bit width , 1G bytes capacity , with the help of signaltap, i found that PHY never return read data valid to controller read request.

But it can works well other two Crucial SODIMM, CT6464AC667(512M bytes capacity) , CT12864AC800(1G bytes). I checked timing parameter , looks like all parameter in the range of JEDEC requirement .

Could anyone give me some hints?

thanks alot

xyzxyk

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with the help of oscilloscope, I found that CT12864AC667 doesn't reply DQS to read command.....

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I am really confused. CT6464A667 should have the same timing parameter as CT12864AC667, why doesn't CT12864AC667 work, but CT6464AC667 works.

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