2440 bare metal program - timer controls LED light flashing

The four programs S3C2440A.s; 2440lib.c; main.c; timer.c need to be added to the project.

Main program:

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

* File name: main.c

* Author: ZXL 

* Description: Use the timer to make the LED light flash once every 0.5 seconds and the buzzer beep once every 0.5 seconds

* History: 2013.5.8

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

#include "def.h"

#include "option.h"

#include "2440addr.h"     

#include "2440lib.h"

void dely(U32 tt)

{

   U32 i;

   for(;tt>0;tt--)

        for(i=0;i<10000;i++);

}

void init()

{

U32 i;

U8 key;

U32 mpll_val=0;

    i = 2 ; 

switch ( i ) //Set the clock frequency of 2440

{

case 0: //200

key = 12;

mpll_val = (92<<12)|(4<<4)|(1);

break;

case 1: //300

key = 13;

mpll_val = (67<<12)|(1<<4)|(1);

break;

case 2: //400

key = 14;

mpll_val = (92<<12)|(1<<4)|(1);

break;

case 3: //440!!!

key = 14;

mpll_val = (102<<12)|(1<<4)|(1);

break;

default:

key = 14;

mpll_val = (92<<12)|(1<<4)|(1);

break;

}

//MDIV=92,PDIV=1,SDIV=1 Determined by configuring MPLLCON, MPLL, that is, FCLK=400MHZ

ChangeMPllValue((mpll_val>>12)&0xff, (mpll_val>>4)&0x3f, mpll_val&3);

ChangeClockDivider(key, 12); //FCLK:HCLK:PCLK = 1:1/4:1/8 =400M:100M:50M

Port_Init();

Uart_Init(0,115200);

    Uart_Select(0);   

Uart_Printf("n flashes once and beeps once every 0.5 seconds!n");

}  

int main(int argc, char **argv)

{

init();

led1_port_init();

beep_init();

timer0_init();

Uart_Printf("nTimer Test beginn"); 

    while(1);

}

Timer program:

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

* File name: timer.c

* Author: ZXL 

* Description: Use the timer to make the LED light flash once every 0.5 seconds and the buzzer beep once every 0.5 seconds

* History: 2013.5.8

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

#include "def.h"

#include "option.h"

#include "2440addr.h"

#include "2440lib.h"

#define LED1_ON ~(1<<5)

#define LED2_ON ~(1<<6)

#define LED3_ON ~(1<<7)

#define LED4_ON ~(1<<8)

#define LED1_OFF (1<<5)

#define LED2_OFF (1<<6)

#define LED3_OFF (1<<7)

#define LED4_OFF (1<<8)

void led1_port_init()

{

    rGPBCON &= ~(0x3<<10); //Control register clear

    rGPBCON |= (0x1<<10); //Control register is set to output

rGPBDAT |= (LED1_OFF)|(LED2_OFF)|(LED3_OFF)|(LED4_OFF); //All LED lights are off

}

void led1_run()

{

    if(rGPBDAT &(1<<5)) rGPBDAT &=~(1<<5); //The LED light was originally on——> then it turns off

    else rGPBDAT |=(1<<5); //The LED light was off ——> it turns on

}

void beep_init()

{

rGPBCON &= ~(3<<0); //Control register clear

rGPBCON |= (1<<0); //Control register is set to output

}

void beep_run()

{

    if(rGPBDAT &(1<<0)) rGPBDAT &=~(1<<0); //Buzzer beeps——> then stops

    else rGPBDAT |=(1<<0); //Buzzer stops——> then it will beep

}

void __irq IRQ_Timer0_Handle(void)

{

if(rINTPND==BIT_TIMER0) //If BIT_TIMER0 triggers an interrupt, the corresponding BIT_TIMER0 bit in the INTPEND register is set to 1

     ClearPending(BIT_TIMER0); // Clear BIT_TIMER0 interrupt

    led1_run(); //LED flashes

beep_run(); //Buzzer beeps

}

void timer0_init()

{

  rTCFG0 = 49; //The first 50 division pclk/(49+1)=50M/50=1M

  rTCFG1 = 0x03; //The second 16-division frequency = 62500HZ = 1M/16

  rTCNTB0 = 62500/2; //TCNTB0[15:0]=count value  

  rTCMPB0 = 0;

  rTCON |=(1<<1); //Load the count value into TCNTB0, TCMPB0

  rTCON =0x09; //Start timer 0 and automatically reload

  rINTMOD = 0x0; // Set to IRQ mode   

  ClearPending(BIT_TIMER0); // Clear BIT_TIMER0 interrupt

  pISR_TIMER0 = (U32)IRQ_Timer0_Handle; //Correspond the timer execution function to the timer interrupt entry address

  EnableIrq(BIT_TIMER0); //Enable BIT_TIMER0 interrupt

  Uart_Printf("n interrupt type INTMSK=0x%xn",rINTMSK); //Display the internal type of interrupt that the CPU will service 1: shield 0: serviceable

}