STM32 GPIO Speed

Introduction

The measurements were done on a STM32F429 Discovery Board using pin PG5 because that pin was close to a GND pin on the header. It is using an external crystal of 8 MHz and the PLL inside is set to output a 180 MHz SYSCLK. A Rigol DS1054Z was used to do the measurements.

2 MHz

GPIO_Speed_2MHz (GPIO_Low_Speed):
Rise time ≈ 9.5ns

2 MHz Rise Time

25 MHz

GPIO_Speed_25MHz (GPIO_Medium_Speed):
Rise time ≈ 3.7ns

25 MHz Rise Time

50 MHz

GPIO_Speed_50MHz (GPIO_Fast_Speed):
Rise time ≈ 2.4ns

50 MHz Rise Time

100 MHz

GPIO_Speed_100MHz (GPIO_High_Speed):
Rise time ≈ 1.9ns

100 MHz Rise Time