void time_init_1s() { TA1CCTL0 = CCIE; // CCR0 interrupt enabled TA1CCR0 = 16383; TA1CTL = TASSEL_1 + MC_1 + TACLR; // ACLK, Up to CCR0 , clear TAR }
//中断服务程序
#pragma vector=TIMER1_A0_VECTOR __interrupt void TIMER1_A0_ISR(void) { P5OUT ^=BIT4; TA1CCR0 += 16383; // Add Offset to CCR0 }
时钟设置:
void clk_init() { //ACLK = REFO = 32kHz, MCLK = SMCLK = 25MHz WDTCTL = WDTPW + WDTHOLD; // Stop WDT UCSCTL3 |= SELREF_2; // Set DCO FLL reference = REFO UCSCTL4 |= SELA_2; // Set ACLK = REFO __bis_SR_register(SCG0); // Disable the FLL control loop UCSCTL0 = 0x0000; // Set lowest possible DCOx, MODx UCSCTL1 = DCORSEL_7; // Select DCO range 25MHz operation UCSCTL2 = FLLD_1 +762; // Set DCO Multiplier for 25MHz // (N + 1) * FLLRef = Fdco // (762 + 1) * 32768 = 25MHz // Set FLL Div = fDCOCLK/2 __bic_SR_register(SCG0); // Enable the FLL control loop // Worst-case settling time for the DCO when the DCO range bits have been // changed is n x 32 x 32 x f_MCLK / f_FLL_reference. See UCS chapter in 5xx // UG for optimization. // 32 x 32 x 25 MHz / 32,768 Hz = 782000 = MCLK cycles for DCO to settle __delay_cycles(782000); // Loop until XT1,XT2 & DCO fault flag is cleared do { UCSCTL7 &= ~(XT2OFFG + XT1LFOFFG + XT1HFOFFG + DCOFFG); // Clear XT2,XT1,DCO fault flags SFRIFG1 &= ~OFIFG; // Clear fault flags }while (SFRIFG1&OFIFG); // Test oscillator fault flag }
//****************************************************************************** // MSP430F5438 Demo - Timer_A3, Toggle P1.0;P2.1-3, Cont. Mode ISR, 32kHz ACLK // // Description: Use Timer1_A CCRx units and overflow to generate four // independent timing intervals. For demonstration, CCR0, CCR1 and CCR2 // output units are optionally selected with port pins P2.1, P2.2 and P2.3 // in toggle mode. As such, these pins will toggle when respective CCRx // registers match the TAR counter. Interrupts are also enabled with all // CCRx units, software loads offset to next interval only - as long as // the interval offset is added to CCRx, toggle rate is generated in // hardware. Timer1_A overflow ISR is used to toggle P1.0 with software. // Proper use of the TAIV interrupt vector generator is demonstrated. // ACLK = TACLK = 32kHz, MCLK = SMCLK = default DCO ~1.045MHz // // As coded and with TACLK = 32768Hz, toggle rates are: // P2.1= CCR0 = 32768/(2*4) = 4096Hz // P2.2= CCR1 = 32768/(2*16) = 1024Hz // P2.3= CCR2 = 32768/(2*100) = 163.84Hz // P1.0= overflow = 32768/(2*65536) = 0.25Hz // // MSP430F5438 // ------------------- // /|\| | // | | | // --|RST | // | | // | P2.1/TA1.0|--> CCR0 // | P2.2/TA1.1|--> CCR1 // | P2.3/TA1.2|--> CCR2 // | P1.0|--> Overflow/software // | P1.0|--> LED // // M Smertneck / W. Goh // Texas Instruments Inc. // September 2008 // Built with CCE Version: 3.2.2 and IAR Embedded Workbench Version: 4.11B //****************************************************************************** #include "msp430x54x.h" void main(void) { WDTCTL = WDTPW + WDTHOLD; // Stop WDT P2SEL |= 0x0E; // P1.1 - P1.3 option select P2DIR |= 0x0E; // P2.1 - P2.3 outputs P1DIR |= 0x01; // P1.0 - Outputs TA1CCTL0 = OUTMOD_4 + CCIE; // CCR0 toggle, interrupt enabled TA1CCTL1 = OUTMOD_4 + CCIE; // CCR1 toggle, interrupt enabled TA1CCTL2 = OUTMOD_4 + CCIE; // CCR2 toggle, interrupt enabled TA1CTL = TASSEL_1 + MC_2 + TACLR + TAIE; // ACLK, contmode, clear TAR, // interrupt enabled __bis_SR_register(LPM3_bits + GIE); // Enter LPM3, interrupts enabled __no_operation(); // For debugger } // Timer1 A0 interrupt service routine #pragma vector=TIMER1_A0_VECTOR __interrupt void Timer_A0 (void) { TA1CCR0 += 4; // Add Offset to CCR0 } // Timer_A3 Interrupt Vector (TAIV) handler #pragma vector=TIMER1_A1_VECTOR __interrupt void TIMER1_A1_ISR(void) { switch(__even_in_range(TA1IV,14)) { case 0: break; case 2: TA1CCR1 += 16; // Add Offset to CCR1 break; case 4: TA1CCR2 += 100; // Add Offset to CCR2 break; case 6: break; // CCR3 not used case 8: break; // CCR4 not used case 10: break; // CCR5 not used case 12: break; // Reserved not used case 14: P1OUT ^= 0x01; // overflow break; default: break; } }
从datasheet可以看出模式4的波形。
看了两天时钟,定时器,想在写点体会,方法也难,最后还是建议大家多看datasheet,看英文的比较好,中文的太垃圾了