SDIO
SDIO=Secure Digital Input/Output
Version of Secure Digital used to connect peripherals.
Three different modes are supported:
- SD 4-bit mode (mandatory on high-speed cards)
- SD 1-bit mode (mandatory on all cards)
- SPI mode (mandatory on all cards)
Pinout
SD 4-bit mode
| Pin | Name | Description |
|---|---|---|
| 1 | CD/DAT[3] | Data line 3 |
| 2 | CMD | Command line |
| 3 | VSS1 | Ground |
| 4 | VDD | Supply voltage |
| 5 | CLK | Clock |
| 6 | VSS2 | Ground |
| 7 | DAT[0] | Data line 0 |
| 8 | DAT[1] | Data line 1 |
| 9 | DAT[2] | Data line 2 |
SD 1-bit mode
| Pin | Name | Description |
|---|---|---|
| 1 | n/c | Not used |
| 2 | CMD | Command line |
| 3 | VSS1 | Ground |
| 4 | VDD | Supply voltage |
| 5 | CLK | Clock |
| 6 | VSS2 | Ground |
| 7 | DATA | Data line |
| 8 | IRQ | Interrupt |
| 9 | RW | Read/Write (optional) |
SPI mode
| Pin | Name | Description |
|---|---|---|
| 1 | CS | Card Select |
| 2 | DI | Data input |
| 3 | VSS1 | Ground |
| 4 | VDD | Supply voltage |
| 5 | CLK | Clock |
| 6 | VSS2 | Ground |
| 7 | DO | Data output |
| 8 | IRQ | Interrupt |
| 9 | n/c | Not used |