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SmartReflex for TMS320C6657CZH25

Mina
Prodigy 20 points
Other Parts Discussed in Thread: TMS320C6657, LM10011

Hi,

We are using TMS320C6657CZH25 and TMS320C6657CZH with LM10011SD.

 

Both TMS320C6657CZH25 and TMS320C6657CZH output  6-bit VCNTL signals by the reset release after the sequence of the power supplies in our board.

These VCNTL signals are corresponding to VCNTL value of register 0x02350014 in bit 21 to 16.

 

The value of register 0x02350014 in TMS320C6657CZH25 is 0x0FFF0000. This is same value in every TMS320C6657CZH25.

In TMS320C6657CZH, the value is different in every device. One of them is 0x07DF0000.

 

CVDD for TMS320C6657CZH is controlled to about 0.9V. But CVDD for TMS320C6657CZH25 is 1.1V, It doesn't change from an initial voltage.

Power consumption of TMS320C6657CZH is from beginning to end steady.

It of TMS320C6657CZH25 keeps increasing depending at the own temperature. It is saturated with about 6-watt.

We think that we have appropriately cooled it.

 

 

 1. Do we keep using TMS320C6657CZH25 in CVDD is 1.1V?

 2. How much is appropriate power consumption of TMS320C6657CZH25?

 3. Should I control CVDD for TMS320C6657CZH25?

 

My best regards.

  • 0
    TI__Mastermind 30825 points

    1.) Yes, if that's what it's putting out on VCNTL that's what it's supposed to operate at.

    2.) That depends on the utilization condtion (Temp, Device Speed, CPU and IP utilization.)  Please use the Power Consumption Model which can be found on the TMS320C6657 <-- Product Page to determine what the worst case power for the particular utilization would be.

    3.) It sounds like you already are controlling it with the LM10011 SR Controller.  But, yes it's required that you control it via Smart Reflex.

    Please not that while the vast majority of 1.25GHz units will have a SR value of 1.1v, not all 1.25GHz units will.

    Best Regards,
    Chad 

  • 0 in reply to Chad Courtney
    Prodigy 20 points

    Hi, Chad

    I wish to express my gratitude for your answer.

     

    We confirmed power consumption of TMS320C6657CZH25 whose CVDD is controled to 1.1V varied greatly in each device.

    Their value of register 0x02350014 is 0x0FFF0000.

    The difference of about one watt exists in them under the same condition.

     

    In inquiring further into the problem, we found TMS320C6657CZH25 with different value of register 0x02350014.

    One of them is 0x0CF30000. Its power consumption indicated a value that was further one watt less.

     

    In CVDD was controled to 1.1V compulsorily, we operated TMS320C6657CZH25 that had 0x0CF30000.

    Its power consumption was smaller than it's  that TMS320C6657CZH25 had 0x0FFF0000.

     

    Can we buy it by selecting the device with small power consumption or more?

     

    Best Regards

  • 0 in reply to Mina
    TI__Mastermind 30825 points

    I assume on the device with 0x0CF30000 in the register that after the SR VCNTL information was passed out to the SR circuit, that it changed to a voltage level lower than 1.1v.  Bits 21:16 are the VCNTL bits, and the value you gave is not one that would represent 1.1V.   

    If it is not resolving to the correct voltage level, then you need to go back and correct the issue.

    Regarding Screening of devices for lower power.  We only provide the power screening to get the devices to be at or below or Power Consumption Model.  We do not perform any special screening below this.  

    The power consumption will vary, but not exceed our power consumption model.  

    Best Regards,
    Chad