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DM368 Overclocking

Currently using DM368. In order to perform HD video encoding, need to send a 74.25 MHz clock to VENC. In order to achieve this, customer configuring the PLLs to get a 74.24 MHz clock on pll2 sysclk 5, but this means the ARM is a bit overclocked at 445.44 MHz (~3% over the DM368's rated 432 MHz). Most of the DM368s we get are fine with this, but some percentage (10-20%?) don't operate correctly.

 Does TI do any qualification of chips prior to shipment as to which ones may be able to sustain a bit of overclocking? Is there any way to source these? At the moment, we have no other way to source the necessary clock, so overclocking seems to be required

  • Hi Kelsey,

    I dont think we have such data. And overclocking is not recommended.

    The only way is to purchase the DM368E chip which allows running on 486/360MHz.

    BR,

    Eason

  • Eason-

    Can you provide the link to the DM368E?  I cannot find the chip online.

  • Hi I suggest contact your TSR directly. This product really exists you can search DM368E in forum.

  • Eason-

    • Is there any way in software to detect      one vs. the other, or is this part simply a DM368 qualified for a higher      clock speed?
    • Is there a recommendation for clock /      PLL settings for this part?
  • Hi Kelsey,

    It should be qualified for higher speed. In DM368 IPNCRDK there is ubl provided which works on ARM@486MHz, DDR@360MHz.

    BR,

    Eason

  • We too are using the DM368 for H.264 video encoding, and we may be seeing similar issues.

    We also are overclocking the system to 446MHz w/ the DDR clock set to 351MHz to meet the 1080i60 vid clock.  And we are constantly using 80-100% of the CPU.

    I am curious as to what you are seeing when you say they "don't operate correctly".

    We seem to get certain units that simply lock up overtime (seemingly randomly and at random time intervals).

    This only happens on specific chips.  Most chips run fine indefinitely.  And similar to you, it seems to be a percentage like 10-20%.  

    Are you seeing something similar to this?  I just clocked down a few of these problem units in the UBL to 432MHz system & 340MHz DDR to see if they will continue to lock up.  I'm under the assumption that all DM368 chips are qualified at this clock rate...

    Let me know.  We are currently trying to debug these lock ups and it would be nice to know if we are on the right track and someone else is seeing something similar.