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problem while reading from DDR 2 memory

Hi to all

I am currently working on DDR2 controller for Burst Lenth 8. My own code is giving good results when i verified with memory model from MICRON. Now my problem is memory on the board is not sending 4 DQS clock pulses. it seems to be sending for burst lenth 4.

some results i observed ........on C.R.O

If i won't Initialize properly it is not responding at all . no DQS nothing is comming . if i initialize it properly its giving DQS signal of two sine clock pulses. If i write with 101010101 .... of each location i am getting two sine clock pulses on DQ pin while reading . if i write with all ZERO's i am getting ZERO' on DQ pin.

so i think inialization is happenig properly. some problem persistence still some where . If any body has IDEA please help me regarding this. with regards...... sudhakar

Reply to
sudhakarmvs
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What are you writing to the DDR's mode registers?

- Brian

Reply to
Brian Drummond

Hi Brian thanks for ur response

s_ddram_ba

Reply to
sudhakarmvs

It's difficult to follow the disconnected bits of code you have posted, but please explain what this line does.

Because, according to the Micron datasheet I have handy

formatting link
(see p. 25) it appears to set the burst length to 4;

What exactly is displaying this, and why does it seem to disagree with the value you are writing above?

- Brian

Reply to
Brian Drummond

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