19.1.4.13.1 SD Card/e.MMC Boot

In the case of activated Card Detect pin in the Boot Configuration Packet, and if the level of the Card Detect pin is high, no communication with SD Card/e.MMC is performed (no IOs toggling). Otherwise, the SD Card/e.MMC access is initiated (IOs toggling).

Supported SD Card Devices

SD Card Boot supports all SD Card memories compliant with the SD Memory Card Specification V3.0. This includes SDMMC cards.

e.MMC with Boot Partition

The ROM code first checks if the e.MMC boot partition is enabled. If enabled, the ROM code reads the first 64 Kbytes of the boot partition and copy them into the internal SRAM.

FAT Filesystem Boot

If no boot partition is enabled on an e.MMC, the boot process continues with a standard SD Card/e.MMC detection, and the ROM code looks for a “boot.bin” file in the root directory of a FAT12/16/32 file system.