Datasheet

Table Of Contents
Figure 34. Logical
structure of a GPIO.
Each GPIO can be
controlled by one of a
number of peripherals,
or by software control
registers in the SIO.
The function select
(FSEL) selects which
peripheral output is in
control of the GPIO’s
direction and output
level, and/or which
peripheral input can
see this GPIO’s input
level. These three
signals (output level,
output enable, input
level) can also be
inverted, or forced
high or low, using the
GPIO control registers.
2.18.2. Function Select
The function allocated to each GPIO is selected by writing to the FUNCSEL field in the GPIO’s CTRL register. See GPIO0_CTRL
as an example. The functions available on each IO are shown in Table 274 and Table 276.
Table 274. General
Purpose Input/Output
(GPIO) User Bank
Functions
Function
GPIO F1 F2 F3 F4 F5 F6 F7 F8 F9
0 SPI0 RX UART0 TX I2C0 SDA PWM0 A SIO PIO0 PIO1 USB OVCUR DET
1 SPI0 CSn UART0 RX I2C0 SCL PWM0 B SIO PIO0 PIO1 USB VBUS DET
2 SPI0 SCK UART0 CTS I2C1 SDA PWM1 A SIO PIO0 PIO1 USB VBUS EN
3 SPI0 TX UART0 RTS I2C1 SCL PWM1 B SIO PIO0 PIO1 USB OVCUR DET
4 SPI0 RX UART1 TX I2C0 SDA PWM2 A SIO PIO0 PIO1 USB VBUS DET
5 SPI0 CSn UART1 RX I2C0 SCL PWM2 B SIO PIO0 PIO1 USB VBUS EN
6 SPI0 SCK UART1 CTS I2C1 SDA PWM3 A SIO PIO0 PIO1 USB OVCUR DET
7 SPI0 TX UART1 RTS I2C1 SCL PWM3 B SIO PIO0 PIO1 USB VBUS DET
8 SPI1 RX UART1 TX I2C0 SDA PWM4 A SIO PIO0 PIO1 USB VBUS EN
9 SPI1 CSn UART1 RX I2C0 SCL PWM4 B SIO PIO0 PIO1 USB OVCUR DET
10 SPI1 SCK UART1 CTS I2C1 SDA PWM5 A SIO PIO0 PIO1 USB VBUS DET
11 SPI1 TX UART1 RTS I2C1 SCL PWM5 B SIO PIO0 PIO1 USB VBUS EN
12 SPI1 RX UART0 TX I2C0 SDA PWM6 A SIO PIO0 PIO1 USB OVCUR DET
13 SPI1 CSn UART0 RX I2C0 SCL PWM6 B SIO PIO0 PIO1 USB VBUS DET
14 SPI1 SCK UART0 CTS I2C1 SDA PWM7 A SIO PIO0 PIO1 USB VBUS EN
15 SPI1 TX UART0 RTS I2C1 SCL PWM7 B SIO PIO0 PIO1 USB OVCUR DET
16 SPI0 RX UART0 TX I2C0 SDA PWM0 A SIO PIO0 PIO1 USB VBUS DET
17 SPI0 CSn UART0 RX I2C0 SCL PWM0 B SIO PIO0 PIO1 USB VBUS EN
18 SPI0 SCK UART0 CTS I2C1 SDA PWM1 A SIO PIO0 PIO1 USB OVCUR DET
19 SPI0 TX UART0 RTS I2C1 SCL PWM1 B SIO PIO0 PIO1 USB VBUS DET
20 SPI0 RX UART1 TX I2C0 SDA PWM2 A SIO PIO0 PIO1 CLOCK GPIN0 USB VBUS EN
RP2040 Datasheet
2.18. GPIO 209