SDIO I/O voltage is 1.8V. Micro SD card operating voltage is 2.7-3.6V.
Would you please recommend one solution?
I do not care SD card read/write speed very much. Whether can we adjust SDIO read/write speed? If yes, would you please inform the speed range?
Just look for SPI level converters/translators…?
SD cards have two interface modes: MMC (managed specification, open source implementation over 4 wire SPI) and SD (private specification, NDA and licence fee to SD Association for access to implementation details).
SD mode is significantly faster, but there’s no open source implementation. If you need faster access to the SD card, then you’re (or your organisation) are going to have to (pay) join the SD Association, implement the SD protocol in your application and then arrange to pay the licence fees.
Check out the info on www.sdcard.org