Table 2-6 and Table 2-7 detail information for configuring a backup boot mode when the primary boot mode fails or returns.

In the case of backup boot mode, configure the MMC/SD card boot mode instead of eMMC boot mode. To achieve this, the following pin settings are required:

1. Select MMC/SD Card Boot Mode using the Backup Boot Mode Pins as defined in Table 2-6.
   • BOOTMODE[1:3] = 0b101 → MMC/SD card boot mode
   Table 2-6 Backup Mode Selection When MCU Only = 0

   Backup Boot Mode Pins			Backup Boot Mode Selected
   3	2	1
   1	0	1	MMC/SD Card

2. Configure MMC/SD Boot Mode Settings
   • BOOTMODE[4:5] = 0b00 → 4-bit bus width, file system (FS) mode
   • BOOTMODE[7] = 0b0 → Select Port 0
   Table 2-7 MMC/SD Boot Configuration Fields

   BOOTMODE Pins	Field	Value	Description
   7	Port	0 1	Port 0 Port 1
   5	Bus Width	0 1	4 bit 1 bit
   4	FS/Raw	0 1	FS mode Raw Mode

   As a result, the DIP switch settings for MMC/SD card backup boot mode are as follows:

   • BOOTMODE SW8[1:8]: X101_00X0
   • MCU_BOOTMODE SW9[1:8]: XXXX_XXXX (not relevant for backup boot configuration)

   To support both primary and backup boot modes using a single eMMC device connected to MMC controller Port 0, use the following unified switch configuration:

   • BOOTMODE SW8[1:8]: 1101_0000
   • MCU_BOOTMODE SW9[1:8]: 0100_0000