[STM32][C/Codesourcery] Inicjalizacja uC. Port GPIO B

Code C - [expand]
 
// Defines of the ports:
// LED PORT PB, pins PB8 to PB15
 
// Definition of addresses for PORTS:
 
#define GPIO_B_ADDRESS    0x40010400 // Main address of the port.
 
#define GPIOx_CRL_OFFSET  0x00000000 // Offset for younger part of CR register
#define GPIOx_CRH_OFFSET  0x00000004 // Offset for older part of CR register
#define GPIOx_IDR_OFFSET  0x00000008 // Offset for input data register
#define GPIOx_ODR_OFFSET  0x0000000c // Offset for output data register.
#define GPIOx_BSRR_OFFSET 0x00000010 // Offset for bit set/reset register
#define GPIOx_BRR_OFFSET  0x00000014 // Offset for bit reset register.
#define GPIOx_LCKR_OFFSET 0x00000018 // Offset for lock register.
 
// Definition of addresses for RCC register:
 
#define RCC_ADDRESS         0x40021000 // Main address of the port.
#define RCC_APB1ENR_OFFSETT 0x00000018
 
void prepareOutputRegisterForLed();
 
int main()
{
    // Initialize portB:
    prepareOutputRegisterForLed();
 
    // Turn off all LEDS:
    *((unsigned int *) GPIO_B_ADDRESS + GPIOx_ODR_OFFSET) = (unsigned int) 0b00000000000000000000000000000000;
 
    // Light odd LEDS:
    *((unsigned int *) GPIO_B_ADDRESS + GPIOx_ODR_OFFSET) = (unsigned int) 0b00000000000000001010101010101010;
 
    return 0;
}
 
void prepareOutputRegisterForLed()
{
 
    // Activating clock for PORT B:
    *((unsigned int *) RCC_ADDRESS + RCC_APB1ENR_OFFSETT) = (unsigned int) 0b00000000000000000000000001000000;
 
    // Setting port B older part as push-pull output working with 2MHz.
    *((unsigned int *) GPIO_B_ADDRESS + GPIOx_CRH_OFFSET) = (unsigned int) 0b00100010001000100010001000100010;