/* ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
    This code transmit a message using the UART peripheral.
   ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ */

/* **************** START *********************** */
/* Libraries, Definitions and Global Declarations */
#include <stdint.h>
#include "main.h"
#include "user_uart.h"

uint8_t msg[] = "Hello\r\n";

void USER_RCC_Init( void );
void USER_GPIO_Init( void );

/* Superloop structure */
int main(void)
{
	/* Declarations and Initializations */
  USER_RCC_Init( );
  USER_GPIO_Init( );
  USER_UART2_Init( );
    /* Repetitive block */
    for(;;){
      USER_UART2_Transmit( msg, sizeof( msg ));  
      GPIOA->BSRR   =	0x1UL << 5U;
    }
}

void USER_RCC_Init( void ){
	/* System Clock (SYSCLK) configuration for 48 MHz */
	FLASH->ACR	&= ~( 0x6UL <<  0U );// 2 HCLK cycles latency, if SYSCLK >=24MHz <=48MHz
	FLASH->ACR	|=  ( 0x1UL <<  0U );// 2 HCLK cycles latency, if SYSCLK >=24MHz <=48MHz
	while(( FLASH->ACR & ( 0x7UL <<  0U )) != 0x001UL );// wait until LATENCY[2:0]=001
	RCC->CR		&= ~( 0x7UL << 11U );// select HSISYS division factor by 1
	while(!( RCC->CR & ( 0x1UL << 10U )));// wait until HSISYS is stable and ready
	RCC->CFGR	&= ~( 0x7UL <<  0U );// select HSISYS as the SYSCLK clock source
	RCC->CFGR	&= ~( 0x1UL << 11U );// select HCLK division factor by 1
}

void USER_GPIO_Init( void ){
  // Enable GPIOA clock
	RCC->IOPENR	  = RCC->IOPENR   |  ( 0x1UL <<  0U );
  // Configure PA5 as output push pull
  GPIOA->BSRR   =	0x1UL << 21U; // Reset PA5 low to turn off LED
  GPIOA->PUPDR  = GPIOA->PUPDR  & ~( 0x3UL << 10U ); // Clear pull-up/pull-down bits for PA5
  GPIOA->OTYPER = GPIOA->OTYPER & ~( 0x1UL <<  5U ); // Clear output type bit for PA5
  GPIOA->MODER  = GPIOA->MODER  & ~( 0x2UL << 10U ); // Set PA5 as output
  GPIOA->MODER  = GPIOA->MODER  |  ( 0x1UL << 10U ); // Set PA5 as output
}