2410beep.c

S3C2410学习的基础资料 大部分实验源码及工程

#include "2410addr.h"
#include "2410lib.h"
#include "def.h"
/****************************************************************************
【功能说明】蜂鸣器PWM测试
****************************************************************************/

void Buzzer_Freq_Set( U32 freq )
{   
	rGPBCON = rGPBCON & ~(3<<0)|(1<<1);//set GPB0 as tout0, pwm output
		
	rTCFG0 = rTCFG0 & ~0xff|15; //prescaler = 15
	rTCFG1 = rTCFG1 & ~0xf|2;//divider = 1/8
			
	rTCNTB0 = (PCLK>>7)/freq;//rTCNTB0=PCLK/{(prescaler+1) * divider *freq}
	rTCMPB0 = rTCNTB0>>1;	//占空比50%
	
	//disable deadzone, auto-reload, inv-off, update TCNTB0&TCMPB0, start timer 0
	rTCON = rTCON & ~0x1f|(0<<4)|(1<<3)|(0<<2)|(1<<1)|(1);
	rTCON &= ~(1<<1);			//clear manual update bit
}

void Buzzer_Stop( void )
{
	rGPBCON &= ~12;			//set GPB1 as output
	rGPBCON |= 4;
	rGPBDAT &= ~1;
}

void Buzzer_PWM_Run( void )
{
	U16 freq = 2000 ;
	Buzzer_Freq_Set( freq ) ;
}