AM3356 DDR3 data rate problem

Itamar Kempler

Other Parts Discussed in Thread: AM3356

Hi,

I have a custom board with the Sitara AM3356 (ZCZ package) and a single chip 16 bit DDR3L (Micron MT41K128M16JT-125).

The processor works fine with the DDR in 303MHz clock (606Mbps data rate), but we can't seem to get it to work at 400MHz (800Mbps data rate).

Any values we try in the DDR configuration that are not the default values result in error.

We follow the direction in the http://processors.wiki.ti.com/index.php/AM335x_DDR_PHY_register_configuration_for_DDR3 but without success.

Any help will be appreciated.

Itamar.

over 9 years ago

0 Biser Gatchev-XID over 9 years ago

TI__Guru**** 393215 points

Hi,

Do you adjust the timing registers for 400MHz? Here is a step-by-step tutorial for DDR tuning: processors.wiki.ti.com/.../Sitara_Linux_Training:_Tuning_the_DDR3_Timings_on_BeagleBoneBlack

0 Brad Griffis over 9 years ago in reply to Biser Gatchev-XID

TI__Guru*** 125430 points

Besides tuning the timings themselves (which you likely already did) you need to be sure to re-do the leveling:

processors.wiki.ti.com/.../AM335x_DDR_PHY_register_configuration_for_DDR3_using_Software_Leveling

In particular, you need to use the spreadsheet to create new seed values. Then use those values as part of the leveling process to get optimized values.

Also, keep in mind if your CAS latency increased there is a read_latency value in DDR_PHY_CTRL_1 must correspondingly increase.

Processors

Processors forum

AM3356 DDR3 data rate problem