AM3354: DDR topology

jianying chen

Part Number: AM3354

I want to use two 8 bit DDR chips instead of one 16 bit DDR chip in my design. What topology is good for ddr placement and layout? Daisy chain , or Y type?

In the following link, Y type is used in PCB Rev1.4. But i cant find PCB REV1.5 and REV1.6 .

processors.wiki.ti.com/.../AM335x_General_Purpose_EVM_Board_Design_Files gp evm&tisearch=Search-EN-Everything

over 7 years ago

0 Biser Gatchev-XID over 7 years ago

TI__Guru**** 393215 points

Please follow the DDR design guidelines outlined in section 7.7.2 of the AM335x Datasheet Rev. J.

0 jianying chen over 7 years ago in reply to Biser Gatchev-XID

Prodigy 40 points

So for DDR3, fly-by is recommended, is it ? Does TI have demo board with 2 chips DDR3 ?

0 Biser Gatchev-XID over 7 years ago in reply to jianying chen

TI__Guru**** 393215 points

Yes, this is correct. Both AM335x GP EVM and AM335x Starter Kit have 2x8-bit DDR3 memory.

0 jianying chen over 7 years ago in reply to Biser Gatchev-XID

Prodigy 40 points

GP EVM is 2x8 DDR2, and Y (T) type is used in PCB. Start kit shematic what I get from TI website is 1x16bit DDR3. So I am not sure how I should place the 2x8-bit DDR3 . If there is a demo design and PCB with 2x8 bit DDR3, that is will be good .

0 Biser Gatchev-XID over 7 years ago in reply to jianying chen

TI__Guru**** 393215 points

jianying chen said:
GP EVM is 2x8 DDR2

This is not true, latest GP EVM designs use 2xDDR3. See

jianying chen said:
Start kit shematic what I get from TI website is 1x16bit DDR3

Sorry, my mistake here.

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AM3354: DDR topology