新唐M031学习笔记（一）定时器基础计数应用

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);
}

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}
}

#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);
}