STM32L051 GPIO errata

Posted on July 25, 2015 at 15:25

Hello,

I'm having trouble getting the GPIOs work in STM32L051. According to the errata sheet I'm supposed to wait some time after allowing the clock for the peripherials so I did so. However, I still can't measure a logical 1 on PA1. The board doesn't have JTAG on it which makes debugging hard. Any ideas?

typedef struct

{

volatile unsigned int Moder;

// ...

} GPIO_Typedef;

typedef struct

{

volatile unsigned int IOP;

volatile unsigned int AHB;

volatile unsigned int APB2;

volatile unsigned int APB1;

} RCCEN_Typedef;

// Define GPIOs

#define GPIOA_BASE_ADDRESS 0x50000000

#define GPIOB_BASE_ADDRESS 0x50000400

#define GPIOA ( ( GPIO_Typedef * ) GPIOA_BASE_ADDRESS )

#define GPIOB ( ( GPIO_Typedef * ) GPIOB_BASE_ADDRESS )

// Define periphery RCC enable

#define RCCEN_BASE_ADDRESS 0x4002102C

#define RCCEN ( ( RCCEN_Typedef * ) RCCEN_BASE_ADDRESS )

int main()

{

char pin = 1;

char mode = 1;

RCCEN->IOP |= 1; // Enable GPIOA clock

Delay(300); // Wait (errata sheet)

// Pin config

GPIOA->Moder &= ~(3 << (pin * 2));

GPIOA->Moder |= (mode << (pin * 2));

// Set pin

GPIOA->BSRR =  1 << pin;

while(1);

return 0;

}