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AD9914 Calibration and IO_Update

Question asked by jferment on Mar 14, 2018
Latest reply on Mar 14, 2018 by jferment

I"m reading the Data Sheet in regards to the DAC calibration procedure.  The Data Sheet states that a required calibration must be manually set and then cleared.  It also states a calibration time.

 

We are implementing a serial interface.

Is that time how long the pulse is meant to be held HIGH, or is that the required time to wait until calibration is finished?  


How does IO_Update before involved?  Is it required?

 

I saw another thread that said to set DAC_CAL =1 , IO UPDATE, DAC_CAL=0 IO UPDATE

 

Where are we supposed to wait.

 

 

2 ) Second question

 

If I am using the profile registers and changing profile select pins do I need to ever strobe IO_UPDATE, the data sheet mentioned "The Profile Select Pins. Digital inputs (active high). Use these pins to select one of eight phase/frequency profiles for the DDS. Changing the state of one of these pins transfers the current contents of all input/output buffers to the corresponding registers. State changes must be set up on the SYNC_CLK pin (Pin 82)."

 

I read that as if I write a Profile register over SPI, I do not need to strobe IO_UPDATE that simply changing the profile pins will update my output.

 

Is this correct?

 

Thanks

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