1、實(shí)驗(yàn)三：定時器1、 實(shí)驗(yàn)原理1.定時器的結(jié)構(gòu)2. 定時器中斷周期3.實(shí)驗(yàn)功能：通過XF管腳控制LED閃動以一定規(guī)律進(jìn)行閃爍。2、 硬件資源及在片外圍電路硬件資源： DSP芯片、CPU、LED、蜂鳴器、電阻、電容等在片外圍電路： 時鐘發(fā)生器、定時器、通用輸入/輸出口等3、 參數(shù)設(shè)置CPU工作時鐘： *clkmd =0x21b3; 0010000110110011 CLKOUT=18M中斷頻率： 9 /* PRSC 4bit*/ 18M/9000=2KHZ4、 實(shí)驗(yàn)流程圖5、 程序#include #include #include #include #include extern void VE

2、CSTART(void);#define TIMER_CTRL TIMER_TCR_RMK( TIMER_TCR_IDLEEN_DEFAULT, /* IDLEEN = 0 */ TIMER_TCR_FUNC_OF(0), /* FUNC = 0 */ TIMER_TCR_TLB_RESET, /* TLB = 1 */ TIMER_TCR_SOFT_BRKPTNOW, /* SOFT = 0 */ TIMER_TCR_FREE_WITHSOFT, /* FREE = 0 */ TIMER_TCR_PWID_OF(0), /* PWID = 0 */ TIMER_TCR_ARB_RESET,

3、/* ARB = 1 */ TIMER_TCR_TSS_START, /* TSS = 0 */ TIMER_TCR_CP_PULSE, /* CP = 0 */ TIMER_TCR_POLAR_LOW, /* POLAR = 0 */ TIMER_TCR_DATOUT_0 /* DATOUT = 0 */ ) /* Create a TIMER configuration structure that can be passed */* to TIMER_config CSL function for initialization of Timer */* control registers

4、. */TIMER_Config timCfg0 = TIMER_CTRL, /* TCR0 */ 0x3400u, /* PRD0 0x3400=13312*/ 14400, /* PRD0 16bit 0x3400=144000=14400*10*/ 9 /* PRSC 4bit*/;/中斷頻率=Fcpu/(9000*1)=144MHz/13312=1kHzUint16 eventId0; /* Create a TIMER_Handle object for use with TIMER_open */TIMER_Handle mhTimer0;volatile Uint16 timer

5、0_cnt = 0;/* Function/ISR prototypes */interrupt void timer0Isr(void);int old_intm;Uint16 tim_val;Uint16 xfchange = 0;Uint16 ms,f;void main(void) /* Initialize CSL library - This is REQUIRED ! */ /*CLS庫的初始化，這是必需的*/ CSL_init(); /* Set IVPH/IVPD to start of interrupt vector table */ /*修改寄存器IVPH，IVPD，重

6、新定義中斷向量表*/ IRQ_setVecs(Uint32)(&VECSTART); /* Temporarily disable all maskable interrupts */*禁止所有可屏蔽的中斷源*/old_intm = IRQ_globalDisable(); /* Open Timer 0, set registers to power on defaults */*打開定時器0，設(shè)置其為上電的的默認(rèn)值，并返回其句柄*/mhTimer0 = TIMER_open(TIMER_DEV0, TIMER_OPEN_RESET);/* Get Event Id associated w

7、ith Timer 0, for use with */* CSL interrupt enable functions. */*獲取定時器0的中斷ID號*/ eventId0 = TIMER_getEventId(mhTimer0);/* Clear any pending Timer interrupts */*清除定時器0的中斷狀態(tài)位*/IRQ_clear(eventId0);/* Place interrupt service routine address at */* associated vector location */*為定時器0設(shè)置中斷服務(wù)程序*/IRQ_plug(eve

8、ntId0,&timer0Isr);/* Write configuration structure values to Timer control regs */*設(shè)置定時器0的控制與周期寄存器*/ TIMER_config(mhTimer0, &timCfg0); /* Enable Timer interrupt */*使能定時器的中斷*/IRQ_enable(eventId0); /* Enable all maskable interrupts */*設(shè)置寄存器ST1的INTM位，使能所有的中斷*/IRQ_globalEnable(); /* Start Timer */*啟動定時器

9、0*/TIMER_start(mhTimer0);ms=0;for(;)/ Wait for at least 10 timer periods /等待10個定時周期if(xfchange = 0) /點(diǎn)亮XF的LED CHIP_FSET(ST1_55,XF,1); else/關(guān)掉XF的LED CHIP_FSET(ST1_55,XF,0); /* Restore old value of INTM */*恢復(fù)INTM舊的值*/IRQ_globalRestore(old_intm);/* We are through with timer, so close it */*關(guān)掉定時器0*/TIMER_close(mhTimer0); /*定時器0的中斷程序*