PIO Functions
The PIO module may be configured as GPIO or as the aforementioned communication interfaces. The following table describes all PIO functions.
| PIO # | Default Function | I/O | Description | Alternate Function |
|---|---|---|---|---|
| 0 | GPIO | I/O | - | SPI master MISO SPI flash D0 |
| 1 | GPIO | I/O | - | SPI master MOSI SPI flash D1 |
| 2 | GPIO | I/O | - | PWM0 UART2 RXD SPI flash WP |
| 3 | GPIO | I/O | - | PWM1 UART2 TXD SPI flash HOLD |
| 4 | GPIO | I/O | - | SPI master CLK SPI flash CLK |
| 5 | GPIO | I/O | - | SPI master CSN SPI flash CSN |
| 6 | GPIO | I/O | Controlled by BOOT_MODE when booting: UART1 TXD (if BOOT_MODE is high when booting) SPI slave MISO (if BOOT_MODE is low when booting) |
UART1 TXD SPI slave MISO |
| 7 | GPIO | I/O | Controlled by BOOT_MODE when booting: UART1_RXD (if BOOT_MODE is high when booting) SPI slave MOSI (if BOOT_MODE is low when booting) |
UART1 RXD SPI slave MOSI |
| 8 | GPIO | I/O | Controlled by BOOT_MODE when booting: I2C1 SCL (if BOOT_MODE is high when booting) SPI slave CLK (if BOOT_MODE is low when booting) |
I2C1 SCL SPI slave CLK |
| 9 | GPIO | I/O | Controlled by BOOT_MODE when booting: I2C1 SDA (if BOOT_MODE is high when booting) SPI slave CSN (if BOOT_MODE is low when booting) |
I2C1 SDA SPI slave CSN |
| 10 | GPIO | I/O | Communication interface selection pin. Select from PIO6 to PIO9. Only valid when booting. This pin is pulled up if it is not connected. |
PPS D_SEL 32.768 kHz clock |
| 11 | GPIO | I/O | - | PPS EVENT UART1 RXD |
| 12 | GPIO | I/O | Bootstrap mode selection pin. Select firmware loading address, external/internal Flash or SPI interface. Only valid when booting. This pin is pulled up if it is not connected. |
BOOT MODE PPS RF_READY UART1 TXD |
| 13 | GPIO | I/O | - | I2C2 SCL ODO_DIR EVENT |
| 14 | GPIO | I/O | - | I2C2_SDA ODO_CNT EVENT |
| 15 | GPIO | I/O | - | UART2 TXD LO1_DET |
| 16 | GPIO | I/O | - | UART2 RXD BLK LO2_DET |
| 17 | TMS | I/O | Debug interface | ODO_DR GPIO |
| 18 | TCK | I/O | Debug interface | ODO_CNT GPIO |
If you want to change the I/O alternate function, please contact the UNICORECOMM FAE.