s3c2440定时器中断的应用(2) request, control, status, 定时器

yuyang911220

#define _ISR_STARTADDRESS 0x33ffff00


#define U32 unsigned int


#define pISR_TIMER4
(*(unsigned *)(_ISR_STARTADDRESS+0x58))




#define rSRCPND
(*(volatile unsigned *)0x4a000000)
//Interrupt request status
#define rINTMSK
(*(volatile unsigned *)0x4a000008)
//Interrupt mask control
#define rINTPND
(*(volatile unsigned *)0x4a000010)
//Interrupt request status


#define rGPBCON
(*(volatile unsigned *)0x56000010)
//Port B control
#define rGPBDAT
(*(volatile unsigned *)0x56000014)
//Port B data
#define rGPBUP
(*(volatile unsigned *)0x56000018)
//Pull-up control B


#define rTCFG0
(*(volatile unsigned *)0x51000000)
//Timer 0 configuration
#define rTCFG1
(*(volatile unsigned *)0x51000004)
//Timer 1 configuration
#define rTCON
(*(volatile unsigned *)0x51000008)
//Timer control
#define rTCNTB4 (*(volatile unsigned *)0x5100003c)
//Timer count buffer 4


void __irq Timer4_ISR(void)
{

static int count;

count ++;

rSRCPND = rSRCPND | (0x1<<14);

rINTPND = rINTPND | (0x1<<14);

//每隔2秒蜂鸣器响一次，持续时间为0.5秒，并伴随着LED亮

if (count % 4 ==0)

rGPBDAT = ~0x1e0;
//蜂鸣器响，LED亮

else if (count % 4 ==1)

rGPBDAT = 0x1e0;
//蜂鸣器不响，LED灭
}




void Main(void)
{

rGPBCON = 0x155555;
//B0输出，给蜂鸣器；B5~B8输出，给LED

rGPBUP
= 0x7ff;



rGPBDAT = 0x1e0;
//蜂鸣器不响，LED灭



rSRCPND = rSRCPND | (0x1<<14);

rINTPND = rINTPND | (0x1<<14);

rINTMSK = ~(0x1<<14);
//打开定时器4中断





rTCFG0 &= 0xFF00FF;

rTCFG0 |= 0xf900;
// prescaler等于249

rTCFG1 &= ~0xF0000;


rTCFG1 |= 0x20000;
//divider等于8，则设置定时器4的时钟频率为25kHz

rTCNTB4 = 12500;
//让定时器4每隔0.5秒中断一次



rTCON &= ~0xF00000;

rTCON |= 0x700000;

rTCON &= ~0x200000 ;
//定时器4开始工作






pISR_TIMER4 = (U32)Timer4_ISR;



while(1)

{


;



}

}