SD Boot Interface Options
The SD_eMMC controllers support three boot modes. The pins used for each boot mode are shaded in the tables in the PMC MIO Pin Table section.
- SD v3.0 using SD_eMMC controller 0
- SD v2.0 using SD_eMMC controller 1
- SD v3.0 using SD_eMMC controller 1
The MIO pin usage is shown in the MIO Boot Interfaces. When a controller is selected to support SD, the eMMC mode cannot be used.
The SD v2.0 boot mode supports the SD2.0 specification. The SD v3.0 boot modes support the SD3.0 specification with an external SD3.0 compliant voltage-level shifter.
In the SD boot modes, the RCU BootROM runs at an SD device clock frequency between 8.7 MHz and 19.3 MHz dependent on the REF_CLK frequency. FAT 16/32 file systems are supported for reading the boot images.
The image search limit for SD boot mode is listed in the Boot Search Limit section.