用示波器上的引脚进行测量时，无法从MOSI引脚或CLK引脚中获取任何数据。
这是我的代码：
void delay（）{
int i;
for(i = 0; i < 1000000; i++);
}
int main（）{
// Enable RCC APB2 clock for SYSCFG (for externalinterrupt)
RCC->APB2ENR |= RCC_APB2ENR_SYSCFGEN;
// Enable RCC APB1 clock for SPI2
RCC->APB1ENR |= (1 << 14);
// GPIOA for pushbutton
RCC->AHB1ENR |= (1 << 0);
// GPIOB for SPI
RCC->AHB1ENR |= (1 << 1);
// GPIOD for LED
RCC->AHB1ENR |= (1 << 3);
////////用于MOSI，MISO och CLK引脚的GPIO B初始化：
GPIOB->MODER |= (2 << (2*13)); //Sets pin 13 as Alternate function
GPIOB->MODER |= (2 << (2*14)); //Sets pin 14 as Alternate function
GPIOB->MODER |= (2 << (2*15)); //Sets pin 15 as Alternate function
GPIOB->OTYPER |= PUSH_PULL_PIN_13;
GPIOB->OTYPER |= PUSH_PULL_PIN_14;
GPIOB->OTYPER |= PUSH_PULL_PIN_15;
GPIOB->OSPEEDR |= OSPEEDR_MEDIUM_PIN_13;
GPIOB->OSPEEDR |= OSPEEDR_MEDIUM_PIN_14;
GPIOB->OSPEEDR |= OSPEEDR_MEDIUM_PIN_15;
GPIOB->PUPDR |= PUPDR_PULLDOWN_PIN_13; // Pull down for CLK
GPIOB->PUPDR |= PUPDR_PULLUP_PIN_14; // Pull up for MISO
GPIOB->PUPDR |= PUPDR_PULLUP_PIN_15; // Pull up for MOSI
GPIOB->AFR[1] |= ALT_FUNC_AF5_PIN_13; // 5 för AF5 till pin 13
GPIOB->AFR[1] |= ALT_FUNC_AF5_PIN_14; // 5 för AF5 till pin 14
GPIOB->AFR[1] |= ALT_FUNC_AF5_PIN_15; // 5 för AF5 till pin 15
//////////按钮的GPIO A初始化
GPIOA->MODER |= MODER_INPUT_PIN_0;
用于LED的GPIO D初始化
GPIOD->MODER |= MODER_OUTPUT_PIN_12; //Sets pin 12 as output
GPIOD->MODER |= MODER_OUTPUT_PIN_13; //Sets pin 13 as output
GPIOD->MODER |= MODER_OUTPUT_PIN_14; //Sets pin 14 as output
GPIOD->MODER |= MODER_OUTPUT_PIN_15; //Sets pin 15 as output
GPIOD->OTYPER |= PUSH_PULL_PIN_12;
GPIOD->OTYPER |= PUSH_PULL_PIN_13;
GPIOD->OTYPER |= PUSH_PULL_PIN_14;
GPIOD->OTYPER |= PUSH_PULL_PIN_15;
GPIOD->OSPEEDR |= OSPEEDR_MEDIUM_PIN_12;
GPIOD->OSPEEDR |= OSPEEDR_MEDIUM_PIN_13;
GPIOD->OSPEEDR |= OSPEEDR_MEDIUM_PIN_14;
GPIOD->OSPEEDR |= OSPEEDR_MEDIUM_PIN_15;
GPIOD->PUPDR |= PUPDR_PULLDOWN_PIN_12; //Frågetecken på denna, ska det vara 0 1 eller 2??
GPIOD->PUPDR |= PUPDR_PULLDOWN_PIN_13; //Frågetecken på denna, ska det vara 0 1 eller 2??
GPIOD->PUPDR |= PUPDR_PULLDOWN_PIN_14; //Frågetecken på denna, ska det vara 0 1 eller 2??
GPIOD->PUPDR |= PUPDR_PULLDOWN_PIN_15; //Frågetecken på denna, ska det vara 0 1 eller 2??
GPIOD->AFR[1] |= ALT_FUNC_AF0_PIN_12; // 0 för AF0 till pin 12
GPIOD->AFR[1] |= ALT_FUNC_AF0_PIN_13; // 0 för AF0 till pin 13
GPIOD->AFR[1] |= ALT_FUNC_AF0_PIN_14; // 0 för AF0 till pin 14
GPIOD->AFR[1] |= ALT_FUNC_AF0_PIN_15; // 0 för AF0 till pin 15
//////// SPI初始化
SPI2->CR1 |= (0 << CR1_CLOCK_PHASE); //Set clockphase in CR1 register
SPI2->CR1 |= (1 << CR1_CLOCK_POLARITY); //Set polarity in CR1 register
SPI2->CR1 |= (4 << CR1_BAUD_RATE); //Set baudrate
SPI2->CR1 |= (1 << CR1_DATA_FRAME_FORMAT); //16-bit transmission
SPI2->CR1 |= (1 << CR1_ENABLE_SPI); //Enable SPI
SPI2->CR1 |= (1 << CR1_MASTER_SELECT); //MASTER SELECTION
SPI2->CR1 |= (1 << CR1_LSB_FIRST); //LSB FIRST
SPI2->CR1 |= (1 << CR1_SLAVE_SELECT); //SSI set
SPI2->CR1 |= (1 << CR1_SW_SLAVE_MANAGE); //SSM, software slave management selected, which means SSI will be used insted of I/O
SPI2->CR1 |= (0 << CR1_RECEIVE_ONLY); //Transmit and Receive
SPI2->CR1 |= (0 << CR1_CRC_TRANSFER); //NOT USED, CRC
//SPI2->CR1 |= (0 << CR1_CRC_CALCULATION); //NOT USED, CRC calculation disabled
//SPI2->CR1 |= (0 << CR1_BIDIOE); //enable transmit-only if set
SPI2->CR1 |= (0 << CR1_BIDIMODE); //1-line bidirectional mode if set
/////////启用外部中断
//SYSCFG->EXTICR[0] |= (0 << 0); //Enable
EXTI->IMR |= (1 << 0); //Enable interrupt
EXTI->RTSR |= (1 << 0); //set Risnig edge interrupt
EXTI->FTSR |= (0 << 0); //falling edge interrupt (disabled)
NVIC_EnableIRQ(EXTI0_IRQn);
SPI2->CR2 |= (1 << 7);
while(1){
GPIOD->ODR |= (1 << 12); // led ON
delay();
GPIOD->ODR &= ~(1 << 12); // led OFF
delay();
}
return 0;
}
void EXTI0_IRQHandler（）{
EXTI->PR |= (1 << 0); //Clears interrupt pending bit
while(1){
GPIOD->ODR |= (1 << 13); //Blå led ON
delay();
GPIOD->ODR &= ~(1 << 13); //Blå led OFF
delay();
// Here I want to Send Data
SPI2->DR |= 0xFF;
}
}
答案 0 :(得分：0)
请使用stm32f407xx.h文件中的适当宏定义。最好阅读：
TIM2->DIER |= TIM_DIER_UIE; /* interrupt enable on 1st channel */
大于：
TIM2->DIER |= (1 << 1); /* interrupt enable on 1st channel */
这将避免混乱，并可能指出您的问题出在哪里。在当前代码格式下，如果正确设置寄存器，则需要花费很多时间。
编辑：好的，闻起来有些香：
GPIOD->AFR[1] |= (0 << (30)); // 5 för AF0 till pin 15
AFR寄存器的每个引脚为4位。您为什么要转移价值30？不应该是28吗？
edit_2：您的按钮是否触发EXTI irq？如果是的话-那不好... 我不记得板上是否有提供按钮反跳功能的硬件，尽管您应该将其放入代码中。现在，中断可能被触发很多次，而不是按1 irq = 1次按钮。
edit_3：
SPI2->CR2 |= (1 << 7);
当TX缓冲区为空时启用irq。缓冲区为空，直到您按下按钮。这会导致不停地调用SPI2中断，并且您尚未为其定义处理程序。尝试阐明您要实现的目标以及应该如何实现。