AM437x DDR3 H/W Leveling

g.f.

Hi,

My customer are having problem with their AM437x custom board.

Two 16bit DDR3L(128M) as 32bit banks are on the board.
When write leveling are enabled, there are problem of write access against upper 16bit DDR3L.
It can't access successfully. But it can write access against lower 16bit DDR3L successfully.

They have following questions:
1.
How to disable write leveling?
I guess only setting '1' against EMIF4D_DDR_PHY_CTRL_1 bit[25] and 
EMIF4D_DDR_PHY_CTRL_1_SHADOW bit[25] will disable the write leveling of Full leveling.
But I want to make me sure. Is it correct?

2.
Is there any information about leveling issue for AM437x?
I checked errata sheet of AM437x but there was no errata of DDR3 Leveling.

best regards,
g.f.

over 8 years ago

0 Biser Gatchev-XID over 8 years ago

TI__Guru**** 393215 points

Hi g.f,

What software are you using? Is the DDR configured according to processors.wiki.ti.com/.../AM437x_DDR_Configuration_and_Programming_Guide ?

0 g.f. over 8 years ago in reply to Biser Gatchev-XID

Guru 15510 points

Hi Biser,

Sorry for posting many questions.

I introduced the TI wiki page to my customer.
So, I believe they configured DDR according to TI wiki.
And refer to GEL file of AM437x EVM and modified for their custom board.

best regard,
g.f.

0 Biser Gatchev-XID over 8 years ago in reply to g.f.

TI__Guru**** 393215 points

Hardware leveling is supported on AM437X. There may be a routing or soldering issue on the board. Have they followed the DDR3 routing guidelines as outlined in section 5.12.8.2.1 of the AM437X Datasheet Rev. B? Especially the matching requirements given is subsection 5.12.8.2.1.6 are very important.

0 g.f. over 8 years ago in reply to Biser Gatchev-XID

Guru 15510 points

Hi Biser,

I told to follow the guideline so I guess they followed the DDR3 routing guidelines.
But I will ask to the customer.

By the way, I need to answer the above questions 1 and 2 to the customer.
Is my guess correct for question 1?
And is there any information about leveling issue for AM437x?

best regards,
g.f.

0 Biser Gatchev-XID over 8 years ago in reply to g.f.

TI__Guru**** 393215 points

No, there is no issue with hardware leveling. As for your first question, yes, these should be the bits to set.

0 g.f. over 8 years ago in reply to Biser Gatchev-XID

Guru 15510 points

Hi Biser,

Thank you for the reply.
I understood.

As you said, maybe it is routing or solder problem. So I will ask to the customer if they followed the guideline or not.
I will close this post for now.
Thank you for the support.

best regards,
g.f.

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AM437x DDR3 H/W Leveling