Series Article Directory
1. Component foundation 2. Circuit design 3. PCB design 4. Component welding 5. Board debugging 6. Program design 7. Algorithm learning 8. Writing exe 9. Testing standards 10. Project examples
Article directory
foreword
An ordinary college student, what can you do to save your future?
The most detailed embedded system designer training manual in history
Embedded hardware and software summary
For you who can't find the direction of struggle after graduating from university (updated from time to time every week)
Shanghai Vocational Aptitude Examination Institute
China Computer Technology Vocational Qualification
Network Shanghai Socialized Evaluation Title Application Guidelines
1. Question:
In the STM8S103F2 manual, there is an AFR2 option, but this option is reserved in STVP, why?
The picture below is the OPTION BYTE in STVP
2. Solutions
Note that the STM8S series, other chip configuration bytes may be different
#define FLASH_EOP 0X04 //标志位
#define FLASH_DUL 0X08 //标志位
void FLASH_Init(void) //端口重映射初始化函数，在此将PC5映射为TIM2_CH1
{
unsigned char *flash_OPT2;
unsigned char *flash_NOPT2;
flash_OPT2=(unsigned char*)0x4803; //OPT2寄存器的ADDR
flash_NOPT2=(unsigned char*)0x4804; //NOPT2寄存器的ADDR,此寄存器的值是OPT2的取反值
//-------------------------------------------------------------
//第一步 初始化FLASH
while( (FLASH_IAPSR & FLASH_DUL) == 0X00 )
{
FLASH_DUKR = 0XAE;
FLASH_DUKR = 0X56;
} //一旦配置失败，此处将陷入死循环。实际使用请加入超时机制，在此省略
//-------------------------------------------------------------
//第二步 对OPT进行编程，首先需要如下操作：开启opt编程
FLASH_CR2 |= 0X80; //OPT = 1
FLASH_NCR2 &= 0X7F; //NOPT = 0
//-------------------------------------------------------------
//第三步 修改内存
1.修改参数，启用复用功能
2.OPT2 和 NOPT2要相反
//修改OPT2
*flash_OPT2 = 0X01; // 0000 0001 AFR0=1，PC5复用为TIM2_CH1其它默认清0
while( (FLASH_IAPSR & FLASH_EOP) == 0 ); //等待操作完成
//修改NOPT2
*flash_NOPT2 = ~*flash_OPT2;
while( (FLASH_IAPSR & FLASH_EOP) == 0 ); //等待操作完成
//一旦配置失败，此处将陷入死循环。实际使用请加入超时机制，在此省略
//-------------------------------------------------------------
//第四步 对OPT进行编程，最后需要如下操作：禁用opt编程
FLASH_CR2 &= ~0X80; //OPT = 1
FLASH_NCR2 |= 0X80; //NOPT = 0
}
Three, thinking analysis
First of all, understand what we configure in STVP
as shown above, which means that we configure the remapping of I/O ports. Then why can't we operate the register, write it in the software, we don't need to configure it when programming it ourselves, the above code is to directly program the register (OPT2 register)
This is the source of the above code