AnsweredAssumed Answered

Spread spectrum of i.MX6Dual.

Question asked by Takashi Takahashi on Apr 25, 2016
Latest reply on Apr 27, 2016 by Takashi Takahashi

Hi community.

 

Our customer has question below.

 

They are  use the Spread Spectrum in the System PLL.

Setting are below.

CCM_ANALOG_PLL_SYS_SS =0x00DC8001 (stop=220,step=1)

CCM_ANALOG_PLL_SYS_DENOM=0x000003E8 (DENOMB=1000)

Spread spectrum range=5.28MHz (1% of 528MHz )

Frequency change step=24KHz

Modulation frequency=54.55KHz

 

Was set as described above, by using a timer of  GPT, the period of output pulse from the GPIO becomes than 2.5% longer before setting.

 

 

This 2.5% became longer is correct  ?

 

  Please tell me the reason and calculation method to be 2.5%, also what kind of rounding in this case ?

 

Thnks,

Best.

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