목차
[WAT-STM32-2.8] 06번 예제 40MHz로 동작
WAT-STM32-2.8 예제 중 6번째로 40MHz로 동작하는 예제입니다.
LED2 를 1초 간격으로 ON/OFF 하는데 delay의 파라메터 값이 달라집니다.
주요 코드
// WAT_STM3228_06 40MHz로 동작
// 1초 간격으로 LED2 ON/OFF
//
// 출처: https://docs.whiteat.com/?p=3571
//
#define __IO volatile
typedef unsigned int uint32_t;
typedef __IO uint32_t vu32;
typedef unsigned short int uint16_t;
#define GPIO_Pin_0 ((uint16_t)0x0001) /*!< Pin 0 selected */
#define GPIO_Pin_1 ((uint16_t)0x0002) /*!< Pin 1 selected */
#define GPIO_Pin_2 ((uint16_t)0x0004) /*!< Pin 2 selected */
#define GPIO_Pin_3 ((uint16_t)0x0008) /*!< Pin 3 selected */
#define GPIO_Pin_4 ((uint16_t)0x0010) /*!< Pin 4 selected */
#define GPIO_Pin_5 ((uint16_t)0x0020) /*!< Pin 5 selected */
#define GPIO_Pin_6 ((uint16_t)0x0040) /*!< Pin 6 selected */
#define GPIO_Pin_7 ((uint16_t)0x0080) /*!< Pin 7 selected */
#define GPIO_Pin_8 ((uint16_t)0x0100) /*!< Pin 8 selected */
#define GPIO_Pin_9 ((uint16_t)0x0200) /*!< Pin 9 selected */
#define GPIO_Pin_10 ((uint16_t)0x0400) /*!< Pin 10 selected */
#define GPIO_Pin_11 ((uint16_t)0x0800) /*!< Pin 11 selected */
#define GPIO_Pin_12 ((uint16_t)0x1000) /*!< Pin 12 selected */
#define GPIO_Pin_13 ((uint16_t)0x2000) /*!< Pin 13 selected */
#define GPIO_Pin_14 ((uint16_t)0x4000) /*!< Pin 14 selected */
#define GPIO_Pin_15 ((uint16_t)0x8000) /*!< Pin 15 selected */
#define GPIO_Pin_All ((uint16_t)0xFFFF) /*!< All pins selected */
#define RCC_APB2Periph_AFIO ((uint32_t)0x00000001)
#define RCC_APB2Periph_GPIOA ((uint32_t)0x00000004)
#define RCC_APB2Periph_GPIOB ((uint32_t)0x00000008)
#define RCC_APB2Periph_GPIOC ((uint32_t)0x00000010)
#define RCC_APB2Periph_GPIOD ((uint32_t)0x00000020)
/************ GPIOB <*************/
typedef struct
{
__IO uint32_t CRL;
__IO uint32_t CRH;
__IO uint32_t IDR;
__IO uint32_t ODR;
__IO uint32_t BSRR;
__IO uint32_t BRR;
__IO uint32_t LCKR;
} GPIO_TypeDef;
typedef struct
{
__IO uint32_t CR;
__IO uint32_t CFGR;
__IO uint32_t CIR;
__IO uint32_t APB2RSTR;
__IO uint32_t APB1RSTR;
__IO uint32_t AHBENR;
__IO uint32_t APB2ENR;
__IO uint32_t APB1ENR;
__IO uint32_t BDCR;
__IO uint32_t CSR;
} RCC_TypeDef;
/********* GPIOB 메모리 지정 *******/
#define PERIPH_BASE ((uint32_t)0x40000000)
#define APB2PERIPH_BASE (PERIPH_BASE + 0x10000)
#define GPIOB_BASE (APB2PERIPH_BASE + 0x0c00)
#define GPIOB ((GPIO_TypeDef *) GPIOB_BASE)
/************ RCC 메모리 지정 *************/
#define AHBPERIPH_BASE (PERIPH_BASE + 0x20000)
#define RCC_BASE (AHBPERIPH_BASE + 0x1000)
#define RCC ((RCC_TypeDef *) RCC_BASE)
void Delay(vu32 nCount);
int main(void)
{
// Clock control register
// Bit17 HSERDY: External high-speed clock ready flag
// Bit16 HSEON: External high-speed clock enable
unsigned char sws = 0;
RCC->CR |= 0X00010000; // HSEON
while(!(RCC->CR>>17)); //HSE 준비될때까지 기다림
// Clock configuration register (RCC_CFGR)
// Bits21:18 PLLMUL: PLL multiplication factor
// Bits10:8 PPRE1: APB low-speed prescaler (APB1)
/* Bit10-8 0x100 100: HCLK divided by 2 */
RCC->CFGR = 0x00000400;
/*
0000：PLL input clock x 2 1000：PLL input clock x 10
0001：PLL input clock x 3 1001：PLL input clock x 11
0010：PLL input clock x 4 1010：PLL input clock x 12
0011：PLL input clock x 5 1011：PLL input clock x 13
0100：PLL input clock x 6 1100：PLL input clock x 14
0101：PLL input clock x 7 1101：PLL input clock x 15
0110：PLL input clock x 8 1110：PLL input clock x 16
0111：PLL input clock x 9 1111：PLL input clock x 16
*/
RCC->CFGR |= 3<<18; // PLL input clock x 5 -> 40MHz
RCC->CFGR |= 1<<16; //1: HSE oscillator clock selected as PLL input clock
RCC->CR |= 1<<24; //1: PLL ON
while(!(RCC->CR>>25)); //0: PLL unlocked 기다림
RCC->CFGR |= 1<<1; //10: PLL selected as system clock
while(sws != 0x2) // 10: PLL used as system clock
{
sws = RCC->CFGR>>2; // Bits3:2 10: PLL used as system clock
sws &= 0x3;
}
/* GPIOB Port Enable*/
RCC->APB2ENR |= RCC_APB2Periph_GPIOB;
/*-- GPIO Mode Configuration speed, input/output -----------------------*/
/*-- GPIOB max speed: 50MHz , General purpose output push-pull ---*/
GPIOB->CRL &= 0xFFFFF0FF;
GPIOB->CRL |= 0x00000300;
while (1)
{
GPIOB->BRR = GPIO_Pin_2;
Delay(0x17FFFF*5); // 40MHz 일때 약 1초
GPIOB->BSRR = GPIO_Pin_2;
Delay(0x17FFFF*5); // 40MHz 일때 약 1초
}
}
void Delay(vu32 nCount) // delay function
{
for(; nCount != 0; nCount--);
}
결과화면
약 1초 간격으로 LED2는 ON/OFF 합니다.
WAT-STM32-2.8보드 전체 예제
제품 구매
WAT-STM32-2.8 [STM32F103RB Board + 2.8인치 TFT LCD 터치 세트] 는 https://kit128.com/goods/view?no=221 에서 구매하실 수 있습니다.
