Issues About LPDDR4 on iMX8 Frequency setting

[shangregister]

Hi All,

Help!

I downloaded the Msacle Tools for mx8m  EVB and i saw the setting about the LPDDR4 Freq is 1600Mhz.

i see the default setting in RPA excel had a value is :1600,800,334,200Mhz.

and i find the Formula in RPA below:

# Formula is DDR_freq = [REF/DIVR1*2*DIVF1/DIVR2*DIVF2*2/2/DIVQ] x 2

so how can i set the freq to another value : e.g.1333,1200Mhz??

and what is the  meaning in Formula variable (REF,DIVR1,DIVQ........) any doc can find??

HansonD

[igorpadykov]

Hi Hanson

I am afraid there is no additional documentation for usage RPA excel tool.

In general for additional info one can check documentation included in

i.MX8 MSCALE SERIES DDR Tool Release (V2.10) 

and linux documentation, sect.2.5.4 Dynamic Bus Frequency

Linux L4.14.98_2.0.0 Documentation

Best regards
igor
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[shangregister]

hi igor

Thank!

i find some detail "ini.MX 8M Dual/8M QuadLite/8M Quad
Applications Processors Reference
Manual" about HW_DRAM_PLL_CFG2_ADDR with that Formula .

and one more is 

when i using the DDR tools to gen code for uboot.

Is it actually follow the uboot setting in linux kernel run??

because i seen some soc uboot ddr freq and kernel freq is difference.

is it need to modify u-boot and kernel for linux?

if yes, where is the kernel setting file?

Best regards

Hanson

[igorpadykov]

Hi Hanson

please check comments on below link describing how change ddr frequency:

i.MX8 MSCALE SERIES DDR Tool Release (V2.10) 

Best regards
igor