I have not seen anything in the simplified spec that indicates that SPI mode is optional for non-SDUC cards.
I often see drivers that do not follow the correct powerup sequence causing the SD cards not to respond correctly trying to initialize them which is likely where the claim that some cards don't support SPI mode comes from.
As for SDUC support, it will work in any SDXC capable host with a SDUC compatible driver. There is a new command that implements a sort of bank switching mechanism to access data beyond 2 TiB. It changes the upper address bits.
I often see drivers that do not follow the correct powerup sequence causing the SD cards not to respond correctly trying to initialize them which is likely where the claim that some cards don't support SPI mode comes from.
As for SDUC support, it will work in any SDXC capable host with a SDUC compatible driver. There is a new command that implements a sort of bank switching mechanism to access data beyond 2 TiB. It changes the upper address bits.
Statistics: Posted by pica200 — Wed Jul 10, 2024 2:25 pm
