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LXI001
Beginner
300 Views

The data written to ddr3 is somewhat different from the data I read

The FPGA I use belongs to Stratix iv, ddr3 belongs to Mircon, ddr3 's clock is 300mhz, the width of DQ is 16 bits.Both write bursts and read burst addresses are maintained at 0, and burst lengths are 6.I wrote the same data continuously in ddr3, wrote a burst of action, and began to read. When I simulate and use the simulation model given by the example, the data I write is the same as the data I read, and when I use the actual FPGA, the data written and read is somewhat different, but not completely wrong.

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3 Replies
LXI001
Beginner
75 Views

read_from_model.pngwrite_to_simualtion_model.png

LXI001
Beginner
75 Views

2019-11-20_114444.png2019-11-20_114305.pngthe simualation results looks like is right,but signaltap_ii sample results is wrong.2019-11-20_114211.pngsample_write.png

Deshi_Intel
Moderator
75 Views

Hi,

 

There are couple of reasons that I can think why it may failed on hardware but passed on sim.

 

  1. Can you check your Quartus design to ensure it's timing clean with positive margin on Quartus timequest DDR report ?
  2. Pls ensure all DDR3 IP setting is set correctly (DDR3 timing parameter, board setting) that matched with your board layout and DDR3 DRAM used.
  3. Another factor will be to review your board schematic design. Either wrong DDR3 connection on board or certain FPGA power or DDR3 SDRAM is not power up correctly.
  4. Lastly could be also due to bad signal integrity on board. You need to probe DQ, DQS, address or command bus to double check

 

Alternately, you can also try using DDR3 example design (that matched with your DDR3 SDRAM setting) generated from UNIPHY IP to test on your board to see if it make a difference.

 

Thanks.

 

Regards,

dlim

 

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