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AD5313R spi programming problem

I am testing a board that has a AD5313R DAC by bit banging the SPI signals.  I have LDAC and Gain tied to ground.  I am clocking the part at about 200 Hz (very low speed).  My problem is that occasionally when I set a value the output will go to zero or the output will turn off.  I can consistently program the DACB to 32 dec and then program it to 64 dec and the DACB output will turn off.  If I send a command to turn DACB on it has the correct output voltage for value of 64 dec.

 

I have a logic analyzer on the SPI bus and it does not show any issues.  Except when this happens the output voltages I program are correct.  I have some similar issues when programming DACA but I have repeated the above sequence many times.

 

I am using command 3 (Write to and update DAC Channel n) to program the DACs.

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  • Hi Shuang,

    I am afraid we do not provide support for the software. However, if you are having problems using the ADSP-BF706, you may post a question in the ADSP-BF70x sub-community under theBlackfin Processors community.

    For the DAC side of the questions, could you explain how the 0x0200 and 0x0031 will be a valid write to the SDI pin of the AD5313R? Please take note that the data sheet will require you to follow the input shift register content to communicate to the DAC as seen below.

    Regards,

    Mark

Reply
  • Hi Shuang,

    I am afraid we do not provide support for the software. However, if you are having problems using the ADSP-BF706, you may post a question in the ADSP-BF70x sub-community under theBlackfin Processors community.

    For the DAC side of the questions, could you explain how the 0x0200 and 0x0031 will be a valid write to the SDI pin of the AD5313R? Please take note that the data sheet will require you to follow the input shift register content to communicate to the DAC as seen below.

    Regards,

    Mark

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