SD Express adds PCIe and NVMe to the SD card form factor achieving up to 985 MB/s while remaining backward compatible with SDXC slots.
| Pin | Name | Function | Type |
|---|---|---|---|
| 1 | DAT3/PCIe_RX+ | Data 3 or PCIe RX positive | BUS |
| 2 | CMD/PCIe_RX- | Command or PCIe RX negative | BUS |
| 3 | VSS1 | Ground | GND |
| 4 | VDD | 3.3V supply | PWR |
| 5 | CLK/REFCLK+ | Clock or PCIe reference clock+ | BUS |
| 6 | VSS2 | Ground | GND |
| 7 | DAT0/PCIe_TX+ | Data 0 or PCIe TX positive | BUS |
| 8 | DAT1/PCIe_TX- | Data 1 or PCIe TX negative | BUS |