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Using the Ratio Seed spreadsheet for DDR2 on AM335x

Daisuke Maeda

Guru 20165 points

http://processors.wiki.ti.com/index.php/AM335x_EMIF_Configuration_tips#Using_the_Ratio_Seed_spreadsheet_for_DDR2_and_LPDDR

For the DDR_CK trace, there are two input cell for two x8 memories.
If one x16 memory is used, is only the cell on row of "Byte 0" used?
Is the cell on row of "Byte 1" a blank?

The trace length is set in inches.
Can the decimal point be used?

Best regards,

Daisuke

over 12 years ago

0 Biser Gatchev-XID over 12 years ago

TI__Guru**** 393215 points

Hi Daisuke,

For DDR_CK trace, enter the same value for both bytes. And yes, values should be entered in inches, with decimal point (for example 2.785 - the three digits after the decimal point give 1mil accuracy).

0 Daisuke Maeda over 12 years ago in reply to Biser Gatchev-XID

Guru 20165 points

Hi Biser,

Thank you for your reply.

I understand to enter the trace length as follows.

- For One 16-Bit DDR2 Device

- For Two 8-Bit DDR2 Devices

Is my understanding correct?

Best regards,

Daisuke

0 Biser Gatchev-XID over 12 years ago in reply to Daisuke Maeda

TI__Guru**** 393215 points

For 1x16-bit chip it is correct. For 2x8-bit I think that for Byte 0 CK trace has to be yellow + red.

0 Daisuke Maeda over 12 years ago in reply to Biser Gatchev-XID

Guru 20165 points

Hi Biser,

Thank you for your reply.

I had a mistake in addition. The trace lengths of each net class are close to equal, but are not equal.

I understand to enter the trace length as follows.

- For One 16-Bit DDR2 Device

- For Two 8-Bit DDR2 Devices

Best regards,

Daisuke

0 Biser Gatchev-XID over 12 years ago in reply to Daisuke Maeda

TI__Guru**** 393215 points

Correct!

0 Daisuke Maeda over 12 years ago in reply to Biser Gatchev-XID

Guru 20165 points

Hi Biser,

Thank you for your reply.

Best regards,

Daisuke