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Config.5681 (DAC5681)

thu nguyen
Intellectual 510 points
Other Parts Discussed in Thread: DAC5681

Hi Hamza,

For DAC5681,should I use default values defined in data sheet from page 19-23 except for Config0 and Config10?

1) freq  < 125MHz , Config0=1F, other wise 5F

2) Config 10 varies with frequency accordingly as defined on page 9.

I do not quite understand why Config3=73 when CLK=1000MHz in your previous response?

 

thks,thu

  • 0
    Intellectual 510 points

    Hamza,

    I do not understand why DLL could not set to LOCK Mode when CONFIG10 has value CD,CE,CF etc.. except C0?

    5F
    10
    C0
    70
    00
    00
    0C
    FF
    00
    00
    CD
    00
    00
    00
    00
    00

    thu

  • 0
    TI__Expert 5820 points

    Thu

    1) you need to set DLL_bypass CONFIG5, BIT2 to bypass the DLL (page 21). CONFIG0, BIT6 is just a status indicator for DLL lock and is relevant only if the DLL is being used. It is set by DAC, not the user.

    DLL_bypass : When set, the DLL is bypassed and the LVDS data source is responsible for providing
    correct setup and hold timing.

    2) In my config3 settings, I am using software driven SYNC instead of SYNC pin of the DAC. Refer to page 20 of the datasheet.

    SW_sync: This bit can be used as a substitute for the LVDS external SYNC input pins for both
    synchronization and transmit enable control.
    SW_sync_sel: When set, the SW_sync bit is used as the only synchronization input and the LVDS
    external SYNC input pins are ignored.

  • 0 in reply to thu nguyen
    TI__Expert 5820 points

    Thu

    DAC operation is guaranteed for a particular DAC clock frequency only when you use the data sheet recommended value of CONFIG10 for that clock frequency. Other settings might or might not work but TI provided neither support nor guarantees for settings other than those mentioned in the datasheet.

    CONFIG10 setting CD should work for DCLK between 125-150 MHz.

    Regards,


  • 0 in reply to Hamza Fraz
    Intellectual 510 points

    Hi Hamza,

    I notice that your config.reg5681 file supposes to be used at 1000mhz CLOCK , you set CONFIG10=C0 and CONFIG3=73.

    1) If I want to run 125-150MHz CLOCK can I set: CONFIG00=5F; CONFIG10=CD.(pls see attached)

    2) When CLOCK freq > 125MHz, DLL is ENABLE (green) , does it implies that Bit2 of CONFIG5 is "0" ?

    3) How would you changed my config file for CLOCK : a) 125-150mhz, b) 150-175, c) 175-200mhz?

     

    thks,thu