xD Picture Card is a flash memory format developed by Olympus and Fujifilm for digital cameras. The 18-pin connector uses a parallel NAND Flash interface at 3.3V before SD cards made it obsolete.
| Pin | Name | Function | Type |
|---|---|---|---|
| 1 | VCC | 3.3V supply | PWR |
| 2 | GND | Ground | GND |
| 3 | D0 | Data bit 0 | I/O |
| 4 | D1 | Data bit 1 | I/O |
| 5 | D2 | Data bit 2 | I/O |
| 6 | D3 | Data bit 3 | I/O |
| 7 | D4 | Data bit 4 | I/O |
| 8 | D5 | Data bit 5 | I/O |
| 9 | D6 | Data bit 6 | I/O |
| 10 | D7 | Data bit 7 | I/O |
| 11 | /CE | Chip enable | I/O |
| 12 | /OE | Output enable | I/O |
| 13 | /WE | Write enable | I/O |
| 14 | ALE | Address latch enable | I/O |
| 15 | CLE | Command latch enable | I/O |
| 16 | /WP | Write protect | I/O |
| 17 | R/B | Ready/Busy | I/O |
| 18 | GND | Ground | GND |