This Design Advisory describes an issue observed in eMMC devices requiring CMD6 R1b Busy time greater than 1ms. This impacts the next command after CMD6. For example, STOP(ACMD12) send fails after CMD18 (during the BootROM stage).
This is because BootROM configuration of host controller registers fails when the device is busy. This is an SD-Host specification violation in the BootROM and is not a JEDEC specification violation.
This means that some eMMC parts cannot work as a Primary Boot device. This does not impact any Secondary Boot consideration, and these eMMC parts can still work as Secondary Boot devices.
Affected Devices:
- All Zynq UltraScale+
- Versal - See associated errata document. No failures reported so far in Versal devices.