picnanard
Newbie level 4
Hi,
I am new in DDR3 developments.
I am trying a brute force read/write DDR3 sequence. The test pattern is a 32 bits counter big endian. At first I write a one shot 128 Mbytes packet in then DDR3 and then I read them. This represents approximately one second of data storing. I remark that the 2 first Mbytes of data stored in DDR3 are OK but the all the rest is corrupted. Indeed, as you can see in the Figure below, the highest byte “00” of the 32-bit counter become a “08”.
Bytes that are stored for a “long time”, as the highest byte of my counter, seems to be lost after an unknown time. Is this due to a problem of refresh cycle?
The Chipscope DDR3 data acquisition show this problem may come from DDR3 controller or DDR3 memory.
Is there any limit time duration of data storing in DDR3? Do I reached the refresh cycle time limitation (if any?)? Do I forgot any important parameter?
The Chipscope DDR3 data acquisition when i write in DDR3 memory.(addr f8008)
chipscope_write.png
Thanks,
Test configuration :
ISE 14.7 with MIG7 1.9
MT41K256M16xx – 125, 256 Mbyte – 16 bits.
I am new in DDR3 developments.
I am trying a brute force read/write DDR3 sequence. The test pattern is a 32 bits counter big endian. At first I write a one shot 128 Mbytes packet in then DDR3 and then I read them. This represents approximately one second of data storing. I remark that the 2 first Mbytes of data stored in DDR3 are OK but the all the rest is corrupted. Indeed, as you can see in the Figure below, the highest byte “00” of the 32-bit counter become a “08”.
Bytes that are stored for a “long time”, as the highest byte of my counter, seems to be lost after an unknown time. Is this due to a problem of refresh cycle?
The Chipscope DDR3 data acquisition show this problem may come from DDR3 controller or DDR3 memory.
Is there any limit time duration of data storing in DDR3? Do I reached the refresh cycle time limitation (if any?)? Do I forgot any important parameter?
The Chipscope DDR3 data acquisition when i write in DDR3 memory.(addr f8008)
chipscope_write.png
Thanks,
Test configuration :
ISE 14.7 with MIG7 1.9
MT41K256M16xx – 125, 256 Mbyte – 16 bits.