how to boot from MMC device

Hi Liron,

Beaglebone Black boots from eMMC connected on MMC1. It's best to connect all 8 data lines, because ROM code does not use them during initial boot, but the Linux kernel driver does.

Hi,

thanks for your answer do you know if I need to connect the HW rst of EMMC to the CPU because according to the TRM I dont need to

Do you know if I need to connect PU resistor on the DAT or they defined as H in the CPU

Regards

Liron Rodavsky said:

do you know if I need to connect the HW rst of EMMC to the CPU because according to the TRM I dont need to

This would depend on the eMMC. Some memories have this signal disabled by default (it can be enabled by writing to an eMMC register). In this case you don't need it. However if the eMMC requires a HW reset you will need to connect this signal.

Liron Rodavsky said:

Do you know if I need to connect PU resistor on the DAT or they defined as H in the CPU

The internal pullups are weak (approx. 100uA current), so it might be a good idea to provide external pullups. This would depend on the expected environment - noise, EMI, etc.