---
title: GPIO port
slug: one/hardware/gpio-port
docTags:
createdAt: 2026-06-10T18:09:43.572Z
---
The GPIO port is an expansion connector for external hardware modules. It exposes 3.3 V and 5 V power rails (both EFUSE-protected up to 2 A), USB 2.0 data lines, and a mix of MCU and CPU GPIO pins, which can be configured as pins for I²C, UART, SPI, CAN, PWM, I²S, SPDIF, and ADC inputs, as well as PIO (Programmable I/O) pins.
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## GPIO port schematic
:::Iframe{code="" iframeHeight="500"}
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## GPIO port pinout
| **Description** | **PIN** | **PIN** | **Description** |
| ---------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------- | ------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| 3.3 V Power, up to 2A EFUSE | **3V3** | **GND** | Ground |
| **MCU GPIO 40**
PIO
ADC0
PWM8\_A | **M40** | **M41** | **MCU GPIO 41**
PWM8\_B
ADC0
PIO |
| **CPU GPIO4\_B4\_D**
SPDIF\_RX0\_M0
I2C3\_SDA\_M0
UART2\_RX\_M1
CAN1\_RX\_M2 | **B4** | **B5** | **CPU GPIO4\_B5\_D**
CAN1\_TX\_M2
UART2\_TX\_M1
I2C3\_SCL\_M0
SPDIF\_TX0\_M0 |
| **CPU GPIO4\_B2\_D**
SAI1\_SDO3\_M0
SAI1\_SDI1\_M0
PDM1\_SDI1\_M1
SPI4\_MISO\_M2 | **B2** | **B3** | **CPU GPIO4\_B3\_D**
PWM2\_CH7\_M0
SPI3\_CSN1\_M2
SPI4\_CSN0\_M2
PDM1\_SDI0\_M1
SAI4\_SD0\_M0
SAI1\_SDI0\_M0 |
| **CPU GPIO4\_B0\_D**
SAI1\_SDO1\_M0
SAI1\_SDI3\_M0
PDM1\_CLK1\_M1
SPI4\_CLK\_M2
UART5\_TX\_M1
UART6\_RTSN\_M0
UART2\_RTSN\_M1 | **B0** | **B1** | **CPU GPIO4\_B1\_D**
UART2\_CTSN\_M1
UART6\_CTSN\_M0
UART5\_RX\_M1
SPI4\_MOSI\_M2
PDM1\_SDI2\_M1
SAI1\_SDI2\_M0
SAI1\_SDO2\_M0 |
| **CPU GPIO4\_A6\_D**
SAI4\_LRCK\_M0
PDM1\_CLK0\_M1
SPI3\_MISO\_M2
I2C4\_SDA\_M1
UART6\_RX\_M0
CAN0\_RX\_M2 | **A6** | **A7** | **CPU GPIO4\_A7\_D**
PWM2\_CH6\_M0
SPI3\_CLK\_M2
SAI4\_SDI1\_M0
SAI1\_SDO0\_M0 |
| **CPU GPIO4\_A4\_D**
SAI4\_SCLK\_M0
PDM1\_SDI3\_M1
SPI3\_MOSI\_M2
I2C4\_SCL\_M1
UART6\_TX\_M0
CAN0\_TX\_M2 | **A4** | **A5** | **CPU GPIO4\_A5\_D**
I2C2\_SDA\_M2
UART5\_CTSN\_M1
SPI4\_CSN1\_M2
SAI1\_LRCK\_M0 |
| **CPU GPIO4\_A2\_D**
SAI1\_MCLK\_M0
SAI4\_MCLK\_M0
PWM2\_CH5\_M0 | **A2** | **A3** | **CPU GPIO4\_A3\_D**
PWM2\_CH4\_M1
I2C2\_SCL\_M2
UART5\_RTSN\_M1
SPI3\_CSN0\_M2
SAI1\_SCLK\_M0 |
| 5V Power, up to 2A EFUSE | **5V** | **GND** | Ground |
| CPU USB 2.0 Data+ | **D+** | **D-** | CPU USB 2.0 Data- |