以下是我的程式 我修改 CCR0 =55-1; // PWM Period 頻率 148k跳到145k 但 我需要147k 想詢問 如何正確修改
#include <msp430x16x.h>
#define uchar unsigned char
#define uint unsigned int
#define CPU_F ((double)8000000)
#define delay_us(x) __delay_cycles((long)(CPU_F*(double)x/1000000.0))
#define delay_ms(x) __delay_cycles((long)(CPU_F*(double)x/1000.0))
void init_cpu_clk( void );
void LED_Display(void);
void init_pwm(void);
uchar temp1,temp2,keysym;
void main (void)
{
init_cpu_clk(); //设置系统时钟
init_pwm(); //初始化pwm
P1DIR|=0XF0;
P1OUT|=0XFF;
P5DIR |=0XFF;
P5OUT |=0XFF; //关闭数码管
while(1)
{
temp1=P1IN & 0X01; //读取按键IO口电平
if(temp1 !=0X01) //判断是否有按键被按下
{
delay_ms(100); //按键延时防抖动
temp2=P1IN&0X01;
if(temp2==temp1)
{
while(temp2!=0X01) //等待松开按键
temp2=P1IN&0X01;
{
switch(temp1)
{
case 0x00: P5OUT=0XF1;
CCTL1 = OUTMOD_7; // CCR1 reset/set
CCR1 = 27; // CCR1 PWM duty cycle
break;
}
}
}
}
}
}
//设置系统时
void init_cpu_clk( void )
{
volatile unsigned int i;
WDTCTL = WDTPW + WDTHOLD; // 关闭看门狗
BCSCTL1 &= ~XT2OFF; // 打开XT2时钟
do
{
IFG1 &= ~OFIFG; // Clear OSCFault flag
for (i = 0xFF; i > 0; i--); // Time for flag to set
}while ((IFG1 & OFIFG)); // OSCFault flag still set?
BCSCTL2 |= SELM_2 + SELS; // MCLK= SMCLK= XT2 (safe)
}
void init_pwm(void)
{
P1DIR |= BIT2; // P1.2 to output
P1SEL |= BIT2; // P1.2 to TA0.1
CCR0 =55-1; // PWM Period
TACTL = TASSEL_2 + MC_1; // SMCLK, up mode
// _BIS_SR(LPM0_bits); // Enter LPM0
}
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