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About special boot mode of eMMC4.3/4.4

Question asked by Takayuki Ishii on Jun 15, 2018
Latest reply on Oct 4, 2018 by Takayuki Ishii
Branched to a new discussion

Hello community,


I have some basic question about eMMC4.3/4.4 special boot mode.


My understanding of the difference between special boot mode and normal boot mode

of boot ROM function is a memory location to read initial 4 KB of the program image must contain the IVT,
DCD, and the Boot Data structures.


  In special boot mode, initial 4KB image read from "BOOT area partition" in eMMC to internal OCRAM.

  In normal boot mode, initial 4KB image read from "USER area" in eMMC to internal OCRAM.


1) Is it correct?

    If so, how about main BOOT image?

    It will read from "User area" in both mode?


2) In "special boot mode", could it use plugin image?


3) How to select Boot partition1 or 2 to use it.


4) Table 8-15. SD/MMC frequencies in Reference Manual of i.MX6QP (IMX6DQPRM.pdf),

    Hi-speed of MMC(DDR mode) clock set to 50MHz.

    But boot flow from Figure 8-10 to Figure 8-16, it have no timing to set 50MHz.

    It have only 20 or 40 MHz setup.

    Which timing do eMMC clock set to 50MHz?



Best regards,