Ticket Name: TDA4VM-Q1: bootmode for auto select primary boot device Query Text: Part Number: TDA4VM-Q1 Other Parts Discussed in Thread: TDA2 Hi : The TDA2 have the BOOTMODE。for example ,The first device is SD ,the second is EMMC ,it is convenient to use . however .The tda4 , I need to change bootmode every time for different primary boot device .(SD /EMMC ) So does the tda4 have the same bootmode function as the tda2.? and how to set the bootmode Responses: Hi, On TDA4 as well there is a way to select secondary and primary boot mode with a single set of dip switches. So if ROM code is not able to find a valid bootloader from Primary boot media, it will attempt to boot from secondary boot mode. Now that being said, the options for primary boot mode are limited and Section 4.3.2.2 Backup Boot Mode Selection When MCU Only = 0 of the TRM lists them. From the table above, eMMC as backup boot mode is not supported however MMC/SD is. Regards Karan thanks for your reply. so i understand i can not use a bootmode to achive my idea "the primary boot mode is MMC/SD, the second boot mode is EMMC " it must use a dip switches to change different bootmode . Regards kong Hi Kong, xiangxu kong said: so i understand i can not use a bootmode to achive my idea "the primary boot mode is MMC/SD, the second boot mode is EMMC " That is correct. The SoC doesn't support booting from a backup boot media of eMMC boot partition. Regards Karan