STM32L432KC使用TIM17驱动PB3引脚LED闪烁失败求助

作业任务要求使用TIM17替代TIM16，实现STM32L432KC板载PB3引脚的LED闪烁功能，但程序运行后LED毫无反应。原程序使用TIM16时工作正常，换成TIM17后就失效了，换成TIM15则能正常运行。以下是主程序及寄存器定义头文件的代码：

主程序代码 #

#include "stm32l432kc_sfr.h"

#define DEBUG(X) Serial.printf("%s\t%x\n",#X,X)

#define TIM_SR_UIF (1<<0)

void my_delay(uint32_t time_ms){
  TIM17_SR &= ~TIM_SR_UIF;
  for (uint32_t i=0; i<=time_ms;i++){
    TIM17_CNT=0;
    while((TIM17_SR & TIM_SR_UIF)==0);
    TIM17_SR &= ~TIM_SR_UIF;
  }
}

void setup() {
  RCC_AHB2ENR |=1<<1;
  GPIOB_MODER &= ~(3<<6);
  GPIOB_MODER |=1<<6;

  RCC_APB2ENR |=1<<18; //Register bit 16, 17 or 18
  TIM17_PSC = 79;
  TIM17_ARR = 999;
  TIM17_CR1 |=1;  //set to 1 
}

void loop(){
  GPIOB_BSRR = 1<<3;
  my_delay(500);
  GPIOB_BSRR = 1<<19;
  my_delay(500);
}

寄存器定义头文件代码 #

#define RCC_BASE  0x4002'1000UL
#define RCC_AHB2ENR (*(volatile uint32_t*) (RCC_BASE+0x4c))
#define RCC_APB2ENR (*(volatile uint32_t*) (RCC_BASE+0x60))

#define GPIOB_BASE  0x4800'0400UL
#define GPIOB_MODER (*(volatile uint32_t*) (GPIOB_BASE+0x00))
#define GPIOB_BSRR (*(volatile uint32_t*) (GPIOB_BASE+0x18))

#define TIM16_BASE  0x4001'4400UL 
#define TIM16_CR1 (*(volatile uint32_t*) (TIM16_BASE+0x00))
#define TIM16_SR (*(volatile uint32_t*) (TIM16_BASE+0x10))
#define TIM16_CNT (*(volatile uint32_t*) (TIM16_BASE+0x24))
#define TIM16_PSC (*(volatile uint32_t*) (TIM16_BASE+0x28))
#define TIM16_ARR (*(volatile uint32_t*) (TIM16_BASE+0x2c))

#define TIM17_BASE  0x4001'4800UL
#define TIM17_CR1 (*(volatile uint32_t*) (TIM17_BASE+0x00))
#define TIM17_SR (*(volatile uint32_t*) (TIM17_BASE+0x10))
#define TIM17_CNT (*(volatile uint32_t*) (TIM17_BASE+0x24))
#define TIM17_PSC (*(volatile uint32_t*) (TIM17_BASE+0x28))
#define TIM17_ARR (*(volatile uint32_t*) (TIM17_BASE+0x2C))

#define TIM15_BASE  0x4001'4000UL 
#define TIM15_CR1 (*(volatile uint32_t*) (TIM15_BASE+0x00))
#define TIM15_SR (*(volatile uint32_t*) (TIM15_BASE+0x10))
#define TIM15_CNT (*(volatile uint32_t*) (TIM15_BASE+0x24))
#define TIM15_PSC (*(volatile uint32_t*) (TIM15_BASE+0x28))
#define TIM15_ARR (*(volatile uint32_t*) (TIM15_BASE+0x2C))

内容的提问来源于stack exchange，提问作者Johan Melgarejo