LPC210X定时器查询方式及如何初始化

定时器查询方式定时器初始化:

1、设置定时器分频数,为(x+1)分频

2、匹配通道X中断并复位TxTC

3、比较值(1S定时值)

4、启动并复位TxTC

LPC210X定时器查询方式及如何初始化

如:

T1PR = 99; // 设置定时器0分频为100分频,得110592Hz

T1MCR = 0x03; // 匹配通道0匹配中断并复位T0TC

T1MR0 = 110592/2; // 比较值(1S定时值)

T1TCR = 0x03; // 启动并复位T0TC

T1TCR = 0x01;

研究了好长一段时间,LPC210X的定时器,查询方式定时很简单如上面,但中断方式要操作好多寄存器,太麻烦,一直是一头雾水。好不容易理出了思路,现将一段例程粘贴备忘。

#include 《intrinsics.h》

#include 《stdio.h》

#include 《iolpc2103.h》

// OSC [Hz]

#define FOSC 11059200UL

// Core clk [Hz]

#define FCCLK FOSC

// Per clk [Hz]

#define PCCLK (FOSC/4)

// TImer TIck per second

#define TICK_PER_SEC (4UL)

#define TIM_PER_S(Val) (PCCLK/Val)

#define MAX_TICK_PER TIM_PER_S(20)

#define MIN_TICK_PER TIM_PER_S(5)

// Timer Delta period [ms]

#define DELTA_PER (50UL)

#define TIM_DPER ((PCCLK*DELTA_PER)/1000UL)

#define LED_MASK 1《《18

/*************************************************************************

* 函数名称:irq_handler

* 入口参数:无

* 返回参数:无

* 描 述:IRQ handler

*************************************************************************/

#pragma vector=IRQV

__irq __arm void irq_handler (void)

{

void (*interrupt_function)();

unsigned int vector;

vector = VICVectAddr; //获得中断向量

interrupt_function = (void(*)())vector;

if(interrupt_function != NULL)

{

interrupt_function(); //调用中断指向的函数

}

else

{

VICVectAddr = 0; //清除在VIC中的中断

}

}

/*************************************************************************

* 函数名称: Timer0Handler

* 入口参数: 无

* 返回参数: 无

* 说 明: Timer 0 handler

*************************************************************************/

void Timer0Handler (void)

{

// clear interrupt flag

T0IR_bit.MR0INT = 1;

// Change patern

if ((IOSET & LED_MASK) == 0)

IOSET = LED_MASK; //关闭LED

else

IOCLR = LED_MASK;

//pNextPattern = pNextPattern-》pNextPattern; //调整当前的链表

VICVectAddr = 0;

}

/*************************************************************************

* 函数名称: VicInit

* 入口参数: 无

* 返回参数: 无

* 说 明: Init VIC module

*************************************************************************/

void VicInit (void)

{

// Assign all interrupt chanels to IRQ

VICIntSelect = 0;

// Diasable all interrupts

VICIntEnClear = 0xFFFFFFFF;

// Clear all software interrutps

VICSoftIntClear = 0xFFFFFFFF;

// VIC registers can be accessed in User or privileged mode

VICProtection = 0;

// Clear interrupt

VICVectAddr = 0;

// Clear address of the Interrupt Service routine (ISR) for non-vectored IRQs.

VICDefVectAddr = 0;

// Clear address of the Interrupt Service routine (ISR) for vectored IRQs.

VICVectAddr0 = VICVectAddr1 = VICVectAddr2 = VICVectAddr3 =\

VICVectAddr4 = VICVectAddr5 = VICVectAddr6 = VICVectAddr7 =\

VICVectAddr8 = VICVectAddr9 = VICVectAddr10 = VICVectAddr11 =\

VICVectAddr12 = VICVectAddr13 = VICVectAddr14 = VICVectAddr15 = 0;

// Disable all vectored IRQ slots

VICVectCntl0 = VICVectCntl1 = VICVectCntl2 = VICVectCntl3 =\

VICVectCntl4 = VICVectCntl5 = VICVectCntl6 = VICVectCntl7 =\

VICVectCntl8 = VICVectCntl9 = VICVectCntl10 = VICVectCntl11 =\

VICVectCntl12 = VICVectCntl13 = VICVectCntl14 = VICVectCntl15 = 0;

}

/*************************************************************************

* 函数名称: Init_timer0

* 入口参数: 无

* 返回参数: 无

* 说 明: Init tiner0

*************************************************************************/

void Init_timer0(void)

{

/*

// Init timer

// Reset and stop timer0

T0TCR = 2;

// Set timer counters mode - clock by PCLK

T0CTCR = 0;

// Set timer prescaler

T0PR = 0;

// Set timer period

T0MR0 = PCCLK/TICK_PER_SEC;

// Set mack action - interrupt by MACH0 enable, reset counter

T0MCR = 3;

// No external action

T0EMR = 0;

*/

T0TCR = 2;

T0CTCR = 0;

T0PR = 0;

T0MR0 = PCCLK/TICK_PER_SEC;

T0MCR = 3;

T0EMR = 0;

// Assign to IRQ

VICIntSelect_bit.TIMER0 = 0;

// Set interrupt slots

VICVectAddr0 = (unsigned int) Timer0Handler;

VICVectCntl0_bit.NUMBER = VIC_TIMER0;

VICVectCntl0_bit.ENABLED = 1;

// Timer 0 interrupt enable

VICIntEnable_bit.TIMER0 = 1;

// Enable timer0

T0TCR = 1;

}

/*************************************************************************

* 函数名称: Init_Gpio

* 入口参数: 无

* 返回参数: 无

* 说 明: Init GPIO

*************************************************************************/

void Init_Gpio(void)

{

// Init GPIO

PINSEL0 = PINSEL1 = 0;

// Disable fast IO

SCS_bit.GPIO0M = 0;

// Set pins connect to LEDs as outputs

IODIR = LED_MASK;

// All LEDs off

IOCLR = LED_MASK;

}

/*************************************************************************

* 函数名称: Init_pll

* 入口参数: 无

* 返回参数: 无

* 说 明: Init PLL

*************************************************************************/

void Init_pll(void)

{

// Disable PLL

PLLCON = 0;

// Write Feed

PLLFEED = 0xAA;

PLLFEED = 0x55;

// Set periphery divider /4

APBDIV_bit.APBDIV = 0;

// Set MAM fully enable

MAMCR_bit.MODECTRL = 0;

MAMTIM_bit.CYCLES = 3;

MAMCR_bit.MODECTRL = 2;

}

/*************************************************************************

* 函数名称: main

* 入口参数: 无

* 返回参数: 无

* 描 述: main

*************************************************************************/

void main(void)

{

Init_pll();

// Memory map init flash memory is maped on 0 address

#ifdef FLASH

MEMMAP_bit.MAP = 1;

#else

MEMMAP_bit.MAP = 2;

#endif

__disable_interrupt();

VicInit();

Init_Gpio();

Init_timer0();

__enable_interrupt();

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发布日期:2019年07月14日  所属分类:参考设计