Proteus simulation STM32F103R6 register version of the marquee program

The simplest peripheral of STM32 is the high and low level control of the IO port. Proteus simulates the marquee program of STM32F103R6.

1. Schematic

2. Marquee C program

// 粗略延时函数
static void delay(unsigned int n)
{
	for(unsigned int i=0; i<n; i++)
	{
		for(unsigned int j=0; j<1024; j++)
		{
			for(unsigned int k=0; k<1024; k++)
			{
				__asm("nop");
			}
		}
	}
}

int main(void)
{
	// 使能GPIOB端口时钟
	// RCC起始地址：0X40021000
	// RCC_APB2ENR偏移地址：0X18
	*(unsigned int *)(0X40021000 + 0X18) |= (1 << 3);
	
	// 配置IO口为输出模式
	// CNFy[1:0]： 00 - 通用推挽输出模式
	// MODEy[1:0]：01 - 输出模式，最大速度10MHz
	for(unsigned int i=0; i<8; i++)
	{
		// GPIOB起始地址：0X40010C00
		// GPIOx_CRL偏移地址：0X00
		*(unsigned int *)(0X40010C00 + 0X00) |= (1 << (4*i+0));
		*(unsigned int *)(0X40010C00 + 0X00) &= ~(1 << (4*i+1));
		*(unsigned int *)(0X40010C00 + 0X00) &= ~(1 << (4*i+2));
		*(unsigned int *)(0X40010C00 + 0X00) &= ~(1 << (4*i+3));
	}

	// 设置IO口为高电平，关闭LED灯
	// GPIOB起始地址：0X40010C00
	// GPIOx_ODR地址偏移：0X0C
	*(unsigned int *)(0X40010C00 + 0X0C) |= 0xFF;

	while(1)
	{
		for(unsigned int i=0; i<8; i++)
		{
			// 设置IO口为低电平，打开LED灯
			// GPIOB起始地址：0X40010C00
			// GPIOx_ODR地址偏移：0X0C
			*(unsigned int *)(0X40010C00 + 0X0C) &= ~(1 << i);
			delay(1);
			
			// 设置IO口为高电平，关闭LED灯
			// GPIOB起始地址：0X40010C00
			// GPIOx_ODR地址偏移：0X0C
			*(unsigned int *)(0X40010C00 + 0X0C) |= (1 << i);
			delay(1);
		}
	}
}