I’m working on a design of a carrier board for the Jetson Nano module which needs to have microSD card socket.
Jetson Nano data sheet in the section 4.5 SD /SDIO has a note that states: ‘SD Card functionality is not supported on this interface as it has a fixed 1.8V supply.‘
From the Table 16 SD/SDIO Pin Descriptions in the data sheet it’s clear that this interface pins are of CMOS – 1.8V [CZ] type.
Yet, the NVIDIA Jetson Nano Product Design Guide in section 7.0 SD CARD /SDIO on Figure 20: SD Card Connection Example shows a SD card implementation using 3.3V supply voltage.
Hence, my question: is the Jetson Nano module SDMMC interface 3.3V tolerant? If, yes what the note in the data sheet supposed to mean? If no, how the implementation suggested in the design guide could work if most SD cards would use (at least initially) 3.3V signalling voltage.
Hope someone could clarify my confusion.