1.1 Boot Sequence

Out of factory, the ROM code boots on the SDMMC1 memory interface when an SD Card or e.MMC memory is connected (Card Detect pin is used).

In order to configure a specific boot sequence tailored for the system on another memory type (NAND Flash, QSPI, SPI, SDMMC0 interfaces), the user must write a Boot Configuration Packet in the One Time Programmable (OTP) memory. Refer to the product data sheet, section “Standard Boot Configuration” for details.

If no bootable user application is found, for instance during the first boot in factory when the user application has not been written yet into the external NVM, the ROM code then executes its SAM Boot Assistant (SAM-BA) monitor, which in turn waits for a connection from the SAM-BA tool. Refer to ROM Code Process Flow.