ZCU104 is actually SD2.0 instead of SD3.0?

[softwd]

Hi all,

Just ran into a confusing situation. 

On ZCU104's documentation (ug1267), it claims that ZCU104 supports SD1-3.0; but this conflicts with two things.

1. It conflicts with Vivado default setting, Vivado says “MIO45-51" and SD 2.0 

2. It conflicts with the shcematic, MIO39-44 are not connected, thus SD 3.0 should not be possible. More over, does SD2.0 also requries level shifter?

Also attached, Vivado SD 3.0 interface selection:

What is going on?

Thanks ahead.

[ritakur]

Yes, as you observed. ZCU104 doesn't use an SD3.0-compliant voltage level-translator. it doesn't work on SD3.0.
Vivado Board present is no problem to set as SD2.0.

[softwd]

Thanks, that clears things up!

[softwd]

Although, there are a couple of confusion I still have:

1. Why does boot mode 1110 (SD1-LS) still works without the necessary pin connected, and

2. Why does boot mode 0101 (SD1-2.0) does not work, since it uses essentially the same pin as the zcu104 SD pin?

[ritakur · Accepted solution]

UG1085 mentions that 2.0 mode only supports 3.3V for the I/Os while ZCU104 uses 1.8v MIO setting.