topic Order of DDR calibration function call in i.MX Processors

Order of DDR calibration function call

niklasmolin — Mon, 04 Jun 2018 03:16:13 GMT

In mx6sabresd.c function board_init_f, would it be okay to move function call spl_dram_init to be done after

board_early_init_f?

Since after that function I2C is setup and I get info about the board version to know which DCD table (for DDR calibration) that should be used?

I noticed if I do another spl_dram_init (if I keep the first one) to be called after board_early_init_f, the CPU will not boot up.

Thanks,

Niklas

Re: Order of DDR calibration function call

igorpadykov — Mon, 04 Jun 2018 07:54:20 GMT

Hi Niklas

usually ddr initialization is performed as first step, then other peripherals

are initialized. More proper way to post it on uboot mail list as nxp does not use

spl in its i.MX6 uboot releases.

Best regards
igor
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Re: Order of DDR calibration function call

niklasmolin — Mon, 04 Jun 2018 16:40:19 GMT

Hi Igor.

Thanks for your response.

The question I have is if there could be an issue if I do the DDR calibration after the peripheral clocks etc. are enabled?

Regards,

Niklas

Re: Order of DDR calibration function call

igorpadykov — Mon, 04 Jun 2018 23:41:08 GMT

Hi Niklas

yes there may be potential issues as enabling peripheral clocks

may affect mmdc parent frequency and introduce additional noise

on board.

Regards,

Niklas