用按键控制LED灯的亮灭

用按键控制LED灯的亮灭，当按键按下时，LED灯亮，当按键松开时，LED灯灭。 #include%unsigned char flag; void main(void) {

WDTCTL = WDTPW+WDTHOLD; // Stop WDT P4DIR &=~(BIT2);

P4DIR |= BIT4+BIT5+BIT6; // P4.4,P4.5,P4.6 set as output P4OUT &=~(BIT4+BIT5+BIT6); // set led off P2IE |= BIT6; // enable P2.6 interrupt P2IFG &= ~(BIT6); // clean interrupt flag __enable_interrupt(); // enable interrupt while(1)

{ if((P4IN & 0x04)==0) { P2IFG |= BIT6;} else

{P2IFG &=~BIT6;}}

} // PORT2 interrupt service routine #pragma vector=PORT2_VECTOR __interrupt void port_2(void)

{P4OUT ^=(BIT4+BIT5+BIT6); // set led on

P2IFG &=~BIT6; // clean interrupt flag}

用按键控制LED灯的亮灭，当按键按下时，LED灯亮，当按键松开时，LED灯灭。(查询) #include\void main(void)

{WDTCTL = WDTPW+WDTHOLD; // Stop WDT //setting direction P4DIR &= ~(BIT2); //setting IO for input

P4DIR |= BIT4+BIT5+BIT6; // P4.4,P4.5,P4.6 set as output while (1)

{if ((P4IN & 0x04) == 0) //If key is pressed {P4OUT |= BIT4+BIT5+BIT6; //led on} else{P4OUT &=~(BIT4+BIT5+BIT6); // led off}}}

将ACLK配置为VLOCLK(约为10K)，并将ACLK通过P1.0口输出 #include void main(void)

{WDTCTL = WDTPW + WDTHOLD; //关看门狗

UCSCTL4 |= SELA_1; //将ACLK时钟源配置为VLO； P1DIR |= BIT0;

P1SEL |= BIT0; //将ACLK通过P1.0输出

__bis_SR_register(LPM3_bits);//进入LPM3，SMCLK和MCLK停止，ACLK活动} 设ACLK = XT1 = 32768Hz，并通过P1.0输出。 #include void main(void)

{WDTCTL = WDTPW + WDTHOLD; // Stop watchdog timer P1DIR |= BIT0; // ACLK set out to pin P1SEL |= BIT0;

P5SEL |= BIT4+BIT5; // Select XT1

while(BAKCTL & LOCKIO) // Unlock XT1 pins for operation BAKCTL &= ~(LOCKIO);

UCSCTL6 &= ~(XT1OFF); // XT1 On

UCSCTL6 |= XCAP_3; // Internal load cap

// Loop until XT1 fault flag is cleared do

{UCSCTL7 &= ~(XT2OFFG + XT1LFOFFG + DCOFFG);

SFRIFG1 &= ~OFIFG; // Clear fault flags

}while (SFRIFG1&OFIFG); // Test oscillator fault flag UCSCTL6 &= ~(XT1DRIVE_3); // reduce drive strength

UCSCTL4 |= SELA_0; // ACLK = LFTX1 (by default) __bis_SR_register(LPM3_bits); // Enter LPM3 }

设ACLK = XT1 = 32768Hz，令SMCLK = XT2CLK，MCLK = DCO(默认) = 32 x ACLK = 1048576Hz，ACLK和SMCLK分别通过P1.0和P3.4输出。 #include void main(void) {

WDTCTL = WDTPW + WDTHOLD; // Stop WDT P1DIR |= BIT0; // ACLK set out to pins P1SEL |= BIT0;

P3DIR |= BIT4; // SMCLK set out to pins P3SEL |= BIT4;

while(BAKCTL & LOCKIO) // Unlock XT1 pins for operation BAKCTL &= ~(LOCKIO);

P7SEL |= BIT2+BIT3; // Port select XT2 UCSCTL6 &= ~XT2OFF; // Set XT2 On UCSCTL6 &= ~(XT1OFF); // XT1 On

UCSCTL6 |= XCAP_3; // Internal load cap do

{UCSCTL7 &= ~(XT2OFFG + XT1LFOFFG + DCOFFG);

SFRIFG1 &= ~OFIFG; // Clear fault flags

}while (SFRIFG1&OFIFG); // Test oscillator fault flag

UCSCTL6 &= ~XT2DRIVE0; // Decrease XT2 Drive according to // expected frequency

UCSCTL4 |= SELA_0 + SELS_5; // Select SMCLK, ACLK source andDCO source

while(1); // Loop in place }

设ACLK = TACLK = LFXT1 = 32768, MCLK = SMCLK = DCOCLK = 32×ACLK = 1.048576Mhz，利用Timer_A输出周期为512 /32768 = 15.625ms、占空比分别为75%和25%的PWM矩形波： #include void main(void)

{WDTCTL = WDTPW + WDTHOLD; // Stop WDT while(BAKCTL & LOCKIO) BAKCTL &= ~(LOCKIO); // Unlock XT1 pins for operation UCSCTL6 &= ~(XT1OFF); // XT1 On

UCSCTL6 |= XCAP_3; // Internal load cap // Loop until XT1 fault flag is cleared do

{UCSCTL7 &= ~(XT2OFFG + XT1LFOFFG + DCOFFG);

SFRIFG1 &= ~OFIFG; // Clear fault flags }while (SFRIFG1&OFIFG); // Test oscillator fault flag

P1DIR |= BIT2+BIT3; // P1.2 and P1.3 output P1SEL |= BIT2+BIT3; // P1.2 and P1.3 options select TA0CCR0 = 512-1; // PWM Period

TA0CCTL1 = OUTMOD_7; // CCR1 reset/set

TA0CCR1 = 384; // CCR1 PWM duty cycle TA0CCTL2 = OUTMOD_7; // CCR2 reset/set

TA0CCR2 = 128; // CCR2 PWM duty cycle

TA0CTL = TASSEL_1 + MC_1 + TACLR; // ACLK, up mode, clear TAR __bis_SR_register(LPM3_bits); // Enter LPM3 __no_operation(); // For debugger }

由程序知：P1.2—> TA0CCR1 - 75% PWM，P1.3—> TA0CCR2 - 25% PWM。周期15.625ms

利用定时器实现开发板上的LED灯以1Hz的频率闪烁 #include void main(void)

{ WDTCTL = WDTPW + WDTHOLD; // 关闭看门狗

P4DIR |= BIT4 + BIT5 + BIT6; // P4.4、P4.5、P4.6设为输出 TA0CCTL0 = CCIE; // CCR0中断使能 TA0CCR0 = 16384;

TA0CTL = TASSEL_1 + MC_1 + TACLR; // ACLK, 增计数模式, 清除TAR计数器 __bis_SR_register(LPM0_bits + GIE); // 进入LPM0,使能中断 …… 此处隐藏：4536字，全部文档内容请下载后查看。喜欢就下载吧 ……