HI, This TI reference design TIDM-TM4C129SDRAMNVM Execute from SDRAM with code storage in NVM for high performance MCU may also help. It uses the SSI interface to read the MicroSD card. The assumption is that a PC has already copied the program images to the microSD Card. The MCU merely read the MicroSD from the SSI interface. Refer to the below description the user's guide. 3.2.1 MicroSD Card Boot With SDRAM Code Execution The MicroSD card boot with SDRAM code uses the internal flash of the TM4C1294NCPDT to hold the FAT file system and bootloader. The bootloader configures the QSSI modules to run the FAT file system and EPI to interface to a 512-Mb SDRAM at interface frequency of 60 MHz. You can have multiple images on an microSD card configured during compile time to execute from an EPI address space of 0x6000 0000. You can select one of the image files that the bootloader copies to the EPI peripheralconnected SDRAM. After the image is copied, the Cortex-M4 disables the interrupts, updates the NVIC_VTABLE register to map to the external address map, and jumps to the external address space of 0x6000 0000. All subsequent code execution occurs in the external address space until the next board reset. You must use a PC to copy the images to the microSD Card.
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