126.96.36.199. SD/MMC and eMMC Card Interface Design Guidelines
- SD version 3.01, in addition to 3.0
- Embedded MMC (eMMC) version 4.51 and 5.0, in addition to 4.54
GUIDELINE: Ensure that voltage translation transceivers are properly implemented if using 1.8V SD card operation.
HPS I/O use a fixed voltage level of 1.8 V. Many SD cards have an option to signal at 1.8 V or 3.3 V, although the initial power-up voltage requirement is 3.3 V. In cases when you want to use a 3.3 V SD card, voltage switching is required. To have the correct voltage level to power the card, voltage translation transceivers are required.
Follow the guidelines in the Voltage Switching section of the SD/MMC Controller chapter in the Intel® Agilex™ Hard Processor System Technical Reference Manual
|HPS I/O Bank Voltage||SD Card Voltage||Level Shifter Needed|
|1.8 V||3.0 V||Yes|
|1.8 V||1.8 V||No|