DDR2 issue while booting

anil kumar23

Hi,

I am using two ddr2 with 256*2 = 512MB in my am33xx platform. It is intefraced with EMIF port with Address lines and using D0-D15 for dual ddr2 purpose. I want to use single ddr2 in my existing evm board that mean it should recognize it as 256mb ddr2.

I am removing one ddr2 on my board. is there any issue or any u-boot changes required for recognizing single ddr2 in my processor.

I am using the same u-boot try to run, but it is not booting.

Regard,

Anil

over 10 years ago

0 Biser Gatchev-XID over 10 years ago

TI__Guru**** 393215 points

Your board will not work with a single 8-bit DDR memory on the EMIF. Please see section 7.7.2.2 od the AM335X Datasheet Rev. H for allowed DDR2 configurations.

0 anil kumar23 over 10 years ago in reply to Biser Gatchev-XID

Expert 1190 points

Hi,

Ok, Understood as per datasheet either you can use 16-bit ddr2/ddr3 or two 8-bt combination ddr2/ddr3 correct?

Suppose if i want to use 256mb + 512mb=768mb is it possible or not? any changes required in software u-boot/kernel or simply it will work and show the ram as 768mb directly.

Regards,
Anil

0 Biser Gatchev-XID over 10 years ago in reply to anil kumar23

TI__Guru**** 393215 points

The only two possible configurations are 1x16-bit DDR or 2x8-bit DDRs (for the second configuration both 8-bit DDRs must be the same size). Total DDR memory can be up to 1GByte.

0 anil kumar23 over 10 years ago in reply to Biser Gatchev-XID

Expert 1190 points

You mean to say, i have to use the below configuration right?

1). 128*2 = 256MB (DDR2/DDR3) OR
2). 256*2=512MB (DDR2/DDR3) OR
3). 512*2=1GB DDR2.

Please clarify me.

Regards,
Anil

0 Biser Gatchev-XID over 10 years ago in reply to anil kumar23

TI__Guru**** 393215 points

If you use 8-bit memories, yes, these are correct configurations.

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DDR2 issue while booting