定时器基础计数应用

1万 · 2024-6-22 05:13

先上代码

void Hw_Timer0_Init(void)
{
//20:100ms 200:10ms 2000:1ms 20000:100us 200000:10us
TIMER_Open(TIMER0, TIMER_PERIODIC_MODE, 200000);

/* Update prescale to set proper resolution. */
TIMER_SET_PRESCALE_VALUE(TIMER0, 1);
/* Enable Timer0 interrupt */
TIMER_EnableInt(TIMER0);

NVIC_EnableIRQ(TMR0_IRQn);

TIMER_Start(TIMER0);
}
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可以参考注释修改TIMER_Open的参数，想设置为2 000 000 定时1us没有成功，进hardfalt了，没有去细细研究，后续可能会补上。有需要的可以调用官方参考代码中的TIMER_Delay。

整个工程参考代码，这里修改了串口0的IO口为P14 P15

#include <stdio.h>
#include "NuMicro.h"
#include "hw_uart01.h"
#include "hw_timer0.h"

void SYS_Init(void)
{
/* Unlock protected registers */
SYS_UnlockReg();

/* Enable HIRC clock (Internal RC 48MHz) */
CLK_EnableXtalRC(CLK_PWRCTL_HIRCEN_Msk);

/* Wait for HIRC clock ready */
CLK_WaitClockReady(CLK_STATUS_HIRCSTB_Msk);

/* Select HCLK clock source as HIRC and HCLK source divider as 1 */
CLK_SetHCLK(CLK_CLKSEL0_HCLKSEL_HIRC, CLK_CLKDIV0_HCLK(1));

/* Enable UART0 clock */
CLK_EnableModuleClock(UART0_MODULE);

/* Switch UART0 clock source to HIRC */
CLK_SetModuleClock(UART0_MODULE, CLK_CLKSEL1_UART0SEL_HIRC, CLK_CLKDIV0_UART0(1));

/* Enable IP clock */
CLK_EnableModuleClock(TMR0_MODULE);

/* Select IP clock source */
CLK_SetModuleClock(TMR0_MODULE, CLK_CLKSEL1_TMR0SEL_HIRC, 0);

/* Update System Core Clock */
SystemCoreClockUpdate();

/* UART0 RXD=PA.14 and TXD=PA.15 */
SYS->GPA_MFPH = (SYS->GPA_MFPH & ~(SYS_GPA_MFPH_PA14MFP_Msk | SYS_GPA_MFPH_PA15MFP_Msk))|
                  (SYS_GPA_MFPH_PA14MFP_UART0_TXD | SYS_GPA_MFPH_PA15MFP_UART0_RXD );

/* Enable USCI UART interrupt */
UUART_ENABLE_TRANS_INT(UUART0, UUART_INTEN_RXENDIEN_Msk);
NVIC_EnableIRQ(USCI_IRQn);

/* Lock protected registers */
SYS_LockReg();
}

int main()
{

SYS_Init();

/* Init UART0 to 115200-8n1 for print message */
Hw_Uart0_Init();

Hw_Timer0_Init();

while(1)
{
      printf("Hello World\r\n");

      App_Func_Delay(100000);//1s
}
}

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#include "hw_timer0.h"
#include "NuMicro.h"
#include "stdio.h"

//这里一定要加volatile
//大家可以试试不加会有什么BUG，我这里是100%复现
volatile unsigned int g_delay_time = 0;
volatile unsigned int g_delay_flag = 0;

void Hw_Timer0_Init(void)
{
//20:100ms 200:10ms 2000:1ms 20000:100us 200000:10us
TIMER_Open(TIMER0, TIMER_PERIODIC_MODE, 200000);

/* Update prescale to set proper resolution. */
TIMER_SET_PRESCALE_VALUE(TIMER0, 1);

/* Enable Timer0 interrupt */
TIMER_EnableInt(TIMER0);

NVIC_EnableIRQ(TMR0_IRQn);

TIMER_Start(TIMER0);
}

void App_Func_Delay(unsigned int ms)
{
g_delay_time = ms;

while(0 == g_delay_flag);

g_delay_flag = 0;
}

void TMR0_IRQHandler(void)
{
if(g_delay_time)
{
      g_delay_time--;

      if(0 == g_delay_time)
      {
         g_delay_flag = 1;
      }
}

/* Clear interrupt flag */
TIMER_ClearIntFlag(TIMER0);
}