PIC18F中斷定時(shí)器

//基于MCC18編譯器，使用HI-PICC不可用

//-------------------------------------------- #include

//----------------------------------------------------------------------------

void main (void);

void InterruptHandlerHigh (void);

unsigned int Timeout;

//----------------------------------------------------------------------------

// Main routine

void main ()

{

Timeout = 0;

INTCON = 0x20; //disable global and enable TMR0 interrupt

INTCON2 = 0x84; //TMR0 high priority

RCONbits.IPEN = 1; //enable priority levels

TMR0H = 0; //clear timer

TMR0L = 0; //clear timer

T0CON = 0x82; //set up timer0 - prescaler 1:8

INTCONbits.GIEH = 1; //enable interrupts

TRISD = 0; /* configure PORTD for output */

PORTD=0X00;

while (1)

{

if (Timeout == 1)

{ //timeout?

Timeout = 0; //clear timeout indicor

PORTD++; //PORTD端口二進(jìn)制計(jì)數(shù)

}

}

}

PIC18F452定時(shí)器中斷@ZSTU

//----------------------------------------------------------------------------

// High priority interrupt vector

#pragma code InterruptVectorHigh = 0x08

void InterruptVectorHigh (void)

{ _asm

goto InterruptHandlerHigh //jump to interrupt routine

_endasm

}

//----------------------------------------------------------------------------

// High priority interrupt routine

#pragma code

#pragma interrupt InterruptHandlerHigh

void InterruptHandlerHigh ()

{

if (INTCONbits.TMR0IF)

{ //check for TMR0 overflow

INTCONbits.TMR0IF = 0; //clear interrupt flag

Timeout = 1; //indicate timeout

}

}

//----------------------------------------------------------------------------

PIC18F4520單片機(jī)提供多個(gè)中斷源及一個(gè)中斷優(yōu)先級(jí)功能,可以給大多數(shù)中斷源分配高優(yōu)先級(jí)或者低優(yōu)先級(jí).高優(yōu)先級(jí)中斷向量地址為0008H，低優(yōu)先級(jí)中斷向量地址為0018H。高優(yōu)先級(jí)中斷事伯將中斷所有可參正在進(jìn)行的低優(yōu)先級(jí)中斷。

有10個(gè)寄存器用于控制中斷的操作。它們是：

RCON

INTCON

INTCON2

INTCON3

PIR1和PIR2

PIE1和PIE2

IPR1和IPR2

通常，用三個(gè)位控制中斷源的操作。

標(biāo)志位 表明發(fā)生了中斷事件

使能位 允許程序跳轉(zhuǎn)轉(zhuǎn)到中斷向量地址處執(zhí)行（當(dāng)標(biāo)志位置1時(shí)）

優(yōu)先級(jí) 用于選擇是高優(yōu)先級(jí)還是低先級(jí)，通過(guò)將IPEN位（RCON<7>）置1，可使能中斷優(yōu)先級(jí)功能。當(dāng)使能中斷優(yōu)先級(jí)時(shí)，有2位可使能全局中斷。將GIEH位（INTCON<7>）置1，可使能所有優(yōu)先級(jí)位置1（高優(yōu)先級(jí)）的中斷。將GIEL位（INTCON<6>）置1，可使能所有優(yōu)先級(jí)位清零（低優(yōu)先級(jí)）的中斷。

當(dāng)中斷標(biāo)志位、使能位以及相應(yīng)的全局中斷使能位均被置1時(shí)，程序?qū)⒘⒓刺D(zhuǎn)到中斷地址0008H或0018H，具體地址取決于優(yōu)先級(jí)位的設(shè)置。通過(guò)設(shè)置相應(yīng)的使能位可以禁止單個(gè)中斷。

注意：系統(tǒng)復(fù)位時(shí)IPEN位為零（默認(rèn)狀態(tài)）時(shí)，便會(huì)禁止中斷優(yōu)先級(jí)功能，此時(shí)中斷與PIC16系統(tǒng)中檔單片機(jī)相兼容。在兼容模式下，所有中斷均跳轉(zhuǎn)到地址0008H執(zhí)行。

下面是在SP9608-PIC增強(qiáng)型單片機(jī)開(kāi)發(fā)板利用PIC18F4520單片機(jī)來(lái)實(shí)現(xiàn)的數(shù)字頻率計(jì)數(shù)器功能，程序中使用了T0用為外部信號(hào)源輸入，通TMR0來(lái)實(shí)現(xiàn)對(duì)信號(hào)源的頻率計(jì)數(shù)。TMR3作為定時(shí)器，來(lái)產(chǎn)生1mS數(shù)碼管掃描時(shí)基和1S秒時(shí)基信號(hào)。為了提高頻率計(jì)數(shù)的準(zhǔn)確度，采用中斷嵌套技術(shù)來(lái)完成，將TMR3產(chǎn)生1mS的定時(shí)信號(hào)作為高優(yōu)先級(jí)中斷，TMR0作為頻率計(jì)數(shù)溢出中斷作為低先級(jí)中斷。源程序采用MCC18編譯器和MPLAB7.50版本的集成開(kāi)發(fā)環(huán)境，調(diào)試工具采用ICD2；具體源程序如下：

系統(tǒng)時(shí)鐘：采用外部的12MHz晶振經(jīng)過(guò)內(nèi)部PLL的4倍頻到48MHz。（HS-PLL配置位）

1 #include

2 #define TRUE 1

3 #define FALSE 0

4 #define HIGH 1

5 #define LOW 0

6 rom unsigned char LEDDATA[]=

7 {

8 0x3F,0x06,0x5B,0x4F,0x66,

9 0x6D,0x7D,0x07,0x7F,0x6F,

10 0x40,0x00,

11 };

12 struct TIMER_STRUCT

13 {

14 unsigned int Interval;

15 unsigned char Enable;

16 };

17 struct TIMER_STRUCT Timer1S;

18 struct T0_T1_STRUCT

19 {

20 unsigned int High_Byte;

21 unsigned int Low_Byte;

22 unsigned long Result;

23 };

24 struct T0_T1_STRUCT My_T0,My_T1;

25 struct LED_STRUCT

26 {

27 unsigned char DotPointer;

28 unsigned char ScanPointer;

29 unsigned char Buffer[8];

30 };

31 struct LED_STRUCT NumberLED;

32 void PIC18F_High_isr (void);

33 void PIC18F_Low_isr (void);

34 #pragma code high_vector_section=0x8

35 void high_vector (void)

36 {

37 _asm goto PIC18F_High_isr _endasm

38 }

39 #pragma code low_vector_section=0x18

40 void low_vector (void)

41 {

42 _asm goto PIC18F_Low_isr _endasm

43 }

44 #pragma code

45 //---中斷高優(yōu)先級(jí)---//

46 #pragma interrupt PIC18F_High_isr

47 void PIC18F_High_isr (void)

48 {

49 if(TRUE==PIR2bits.TMR3IF)

50 {

51 PIR2bits.TMR3IF=FALSE;

52 TMR3H=(65536-11965)/256;

53 TMR3L=(65536-11965)%256;

54

55 if(FALSE==Timer1S.Enable)

56 {

57 Timer1S.Interval++;

58 if(1000==Timer1S.Interval)

59 {

60 T0CONbits.TMR0ON=FALSE;

61 Timer1S.Interval=0;

62 Timer1S.Enable=TRUE;

63 }

64 }

65

66 if(LOW==LATAbits.LATA0)LATAbits.LATA0=HIGH;

67 else LATAbits.LATA0=LOW;

68

69 LATD=LEDDATA[NumberLED.Buffer[NumberLED.ScanPointer]];

70 LATE=NumberLED.ScanPointer;

71 NumberLED.ScanPointer++; if(NumberLED.ScanPointer==sizeof(NumberLED.Buffer))NumberLED.ScanPointer=0;

72 }

73 }

74 //---中斷低優(yōu)先級(jí)---//

75 #pragma interruptlow PIC18F_Low_isr

76 void PIC18F_Low_isr (void)

77 {

78 if(TRUE==INTCONbits.TMR0IF)

79 {

80 INTCONbits.TMR0IF=FALSE;

81 My_T0.High_Byte++;

82 }

83

84 }

85 void main(void)

86 {

87 unsigned int i;

88 unsigned long temp;

89

90 Timer1S.Enable=FALSE;

91 Timer1S.Interval=0;

92 My_T0.High_Byte=0;

93 My_T0.Low_Byte=0;

94 My_T1.High_Byte=0;

95 My_T1.Low_Byte=0;

96 for(i=0;i

97 NumberLED.ScanPointer=0;

98 NumberLED.DotPointer=0;

99 TRISAbits.TRISA0=0;

100 LATAbits.LATA0=0;

101 TRISD=0;

102 LATD=0;

103 TRISE=0;

104 LATE=0;

105 T0CONbits.TMR0ON=FALSE;

106 TMR0L=0;

107 TMR0H=0;

108 T0CONbits.T0CS=1;

109 T0CONbits.T0SE=0;

110 T0CONbits.PSA=1;

111 T0CONbits.T08BIT=1;

112 INTCONbits.T0IF=FALSE;

113 INTCONbits.T0IE=TRUE;

114 T0CONbits.TMR0ON=TRUE;

115 T3CON=0x00;

116 TMR3H=(65536-12000)/256;

117 TMR3L=(65536-12000)%256;

118 PIR2bits.TMR3IF=FALSE;

119 PIE2bits.TMR3IE=TRUE;

120 T3CONbits.TMR3ON=TRUE;

121 INTCONbits.GIEH=TRUE;

122 INTCONbits.GIEL=TRUE;

123 RCONbits.IPEN=TRUE;

124 //---設(shè)置中斷優(yōu)先級(jí)---//

125 INTCON2bits.TMR0IP=FALSE;

126 IPR2bits.TMR3IP=TRUE;

127

128 while(1)

129 {

130 if(TRUE==Timer1S.Enable)

131 {

132 My_T0.Result=0;

133 My_T0.Result=My_T0.High_Byte;

134 My_T0.Result<<=8;

135 My_T0.Result|=TMR0L;

136 temp=My_T0.Result;

137 for(i=0;i