DDR2 problem in 8640

[lujunbiao]

In DDR2 memory test, I enable DDR1 memory controller,disable  DDR2 memory controller and set the timing configuration register for the contrller.

I fing d1_mdq5 and d1_mdq16 is wrong occassionaly, is there any method I can use to solve this problem?

[Bulat]

Can you add more details, what is the board? What is the DDR2 memory used on the board? What is the DDR frequency?

Regards,

Bulat

[lujunbiao]

thank you for your reply.

In my design:

sysclk = 100Mhz, 

mpx clock ratio = 4:1 -> mpx clock = 400Mhz

DDR clock MCK = 200Mhz

DDR2 memory chip part number = MT47H128M16RT-25E IT:C

Is there any suggestion for ddr memory map set from the offset address 0x100 to 0x130?

I only use DDRC1 in the design and DDRC2 is not used.

I have two module under test now, the first one is ok in memory pattern test (all 1GB memory space has passed the test)and the second one has wrong bit on mdq5 and mdq16 occassionaly.

Please give me some advice to solve this problem.

[Bulat]

If I am correct, yoiu have four DDR2 chips to get 64-bit memory bus, right?

Can you describe your test when you saw problems with mdq5 and mdq16. What exactly you did?

Regards,

Bulat

[lujunbiao]

DDR2 chips is 64-bit in all.

in windriver ice 2,I execute the demand as follow:

step1: go to address 0x00000000

step2:in command window put in "bfl 0 3c 00000000"

step3:put in "dml 0 10"

then in the window it will list the memory data from DDR

I find the bit5 and bit16 is flop occassionally.

[Bulat]

Unfortunately I do not know windriver ice language, can you explain actions provided by "bfl 0 3c 00000000" and by "dml 0 10"?

[lujunbiao]

bfl 0 3c 00000000 means filling data0x00000000 to address 0x00000000~0x0000003c

dml 0 10 means reading 16 data from address 0x00000000

I have re-solder memory chips on the board (the one  has problem), but in reading test it reply 0xffffffff from all addresses,

what might be the problem?

[Bulat]

It is difficult to guess what is the problem now.  Since the prior memory chips were functional (besides mdq5 and mdq16), and new ones are not functional, I would suspect new chips or problems with soldering.

[lujunbiao]

Hi Bulat

Is there any discription of electrical characteristics of MCK from 8640?