mirror of
https://github.com/rfivet/stm32bringup.git
synced 2024-11-14 00:25:58 -05:00
41 lines
1.2 KiB
C
41 lines
1.2 KiB
C
/* init.c -- middleware initialization
|
|
** Copyright (c) 2020 Renaud Fivet
|
|
*/
|
|
|
|
#define SYSTICK ((volatile long *) 0xE000E010)
|
|
#define SYSTICK_CSR SYSTICK[ 0]
|
|
#define SYSTICK_RVR SYSTICK[ 1]
|
|
#define SYSTICK_CVR SYSTICK[ 2]
|
|
|
|
#define RCC ((volatile long *) 0x40021000)
|
|
#define RCC_AHBENR RCC[ 5]
|
|
#define RCC_AHBENR_IOPBEN 0x00040000 /* 18: I/O port B clock enable */
|
|
|
|
#define GPIOB ((volatile long *) 0x48000400)
|
|
#define GPIOB_MODER GPIOB[ 0]
|
|
#define GPIOB_ODR GPIOB[ 5]
|
|
|
|
int init( void) {
|
|
/* By default SYSCLK == HSI [8MHZ] */
|
|
|
|
/* SYSTICK */
|
|
SYSTICK_RVR = 1000000 - 1 ; /* HBA / 8 */
|
|
SYSTICK_CVR = 0 ;
|
|
SYSTICK_CSR = 3 ; /* HBA / 8, Interrupt ON, Enable */
|
|
/* SysTick_Handler will execute every 1s from now on */
|
|
|
|
/* User LED ON */
|
|
RCC_AHBENR |= RCC_AHBENR_IOPBEN ; /* Enable IOPB periph */
|
|
GPIOB_MODER |= 1 << (1 * 2) ; /* PB1 Output [01], over default 00 */
|
|
/* OTYPER Push-Pull by default */
|
|
/* PB1 output default LOW at reset */
|
|
|
|
return 0 ;
|
|
}
|
|
|
|
void SysTick_Handler( void) {
|
|
GPIOB_ODR ^= 1 << 1 ; /* Toggle PB1 (User LED) */
|
|
}
|
|
|
|
/* end of init.c */
|