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PLL_AUDIO:DIV_SELECT

Question asked by chris olarti on Oct 13, 2016
Latest reply on Oct 13, 2016 by igorpadykov

When configuring the PLL_AUDIO:DIV_SELECT for achieving 632.217MHz to obtain a Sample Frame Rate of 22.050kHz as per i.MX 6Dual/6Quad Applications Processor Reference Manual, Rev. 3, 07/2015, Table 61-7 SSI Bit Clock....

 

The main equation is

PLL output frequency = Fref * (DIV_SELECT + NUM/DENOM)

 

So when replacing values:

 

632.217MHz = 24MHz * (DIV_SELECT + NUM/DENOM)

26.342 = DIV_SELECT + NUM/DENOM

 

DIV_SELECT = 26

NUM = 342

DEOM = 1000

 

However when looking at Table: CCM_ANALOG_PLL_AUDIOn field descriptions, DIV_SELECT has a valid range from 27-54.

 

So the question is: Should the comment for DIV_SELECT change from 27-54 to 26-54?  We are currently using 26, and that is working for us, but we need to make sure we are within the iMX6 limitations.  If 27 is enforced, then can you please help us to configure the proper values for trying to achieve a 22.050 kHz sample rate.

 

 

 

Thanks in advance.

 

Chris Olarti.

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