What is the function of BOOT_CFG[6:4] on iMX7 ?

[wad1]

I'm comparing information obtained from the iMX7 Reference Manual (Rev. 0.1, 08/2016) and the iMX7D SABRE development board schematics (rev D).   They show different definitions for the BOOT_CFG pin 6:4, when booting from an SD/eMMC device.

The Reference Manual (Table 6-41) says that BOOT_CFG[6:4] define the Bus Width, and to use a value of 0 - SD/eSD/SDXC, and value of 1 for MMC/eMMC.

Page 18 of the schematics says that for eMMC, BOOT_CFG[6:4] define the bus width (000 - 1 bit, 001 - 4 bit, etc...) and that for SD, BOOT_CFG[6:4] defines the bus width (000 - 1 bit, 001 - 4 bit, all other values reserved).

Which is correct, the reference manual or the SABRE eval board schematics ?

[Yuri · Accepted solution]

Hello,

   Please use information of the iMX7D SABRE development board schematic.

The Reference Manual will be changed in next release.

Have a great day,

Yuri

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