AM437x two 16bit DDR3L memory placement

g.f.

Hi,

I have a question about AM437x DDR3 memory placement.

We are using two 16-bit DDR3L devices arranged as one 32-bit bank.
Which DDR3L memory should be placed near to processor? Lower data byte or higher data byte?
Or is it irrespective which DDR3L memory is placed near to processor?

In AM437x datasheet(sprs851b) page.176 Figure 5-52,
16bit DDR3 of Lower data byte are placed near to the processor.
But in page.195 Figure 5-77, DDR3 of Lowest data byte are placed farest to the processor,
and Highest data byte are placed nearest to the processor.
So, I guess it is irrespective which DDR3 chip is placed near to processor.

best regards,
g.f.

over 10 years ago

0 Biser Gatchev-XID over 10 years ago

TI__Guru**** 393215 points

Hi g.f,

You are right, there is no requirement which DDR3 chip is nearer to the processor.

0 g.f. over 10 years ago in reply to Biser Gatchev-XID

Guru 15520 points

Hi Biser,

Thank you for the reply.

I'm sorry I have one more question.

I attached the routing of clock, control and address bus with red line which denotes clock will be routed 
first to higher data byte DDR and last in lower data byte DDR.

AM437x DDR3 Routing.pdf

Is this routing available? 
Does CLK/ADDR/CNTRL signal need to be routed to the lower byte DDR first?
Or it doesn't matter which DDR need to be connected first?
I guess it is also irrespective.

best regards,
g.f.

0 Biser Gatchev-XID over 10 years ago in reply to g.f.

TI__Guru**** 393215 points

Your guess is correct.

0 g.f. over 10 years ago in reply to Biser Gatchev-XID

Guru 15520 points

Hi Biser,

Thank you so much.
I understood.

best regards,
g.f.

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AM437x two 16bit DDR3L memory placement