六、相关寄存器分析
TCFG0
	Base Address: 0xC001_8000h (PWM)
	Address = Base Address + 0x00h, Reset Value = 0x0000_0101
Name 	Bit 	Type 	Description 	Reset Value
RSVD 	[31:24] 	– 	Reserved 	–
DEAD ZONE LENGTH 	[23:16] 	RW 	Dead zone length 	8'h0
PRESCALER 1 	[15:8] 	RW 	Prescaler 1 value for Timer 2, 3 and 4 	8'h1
PRESCALER 0 	[7:0] 	RW 	Prescaler 0 value for timer 0 & 1 	8'h1

定时器输入时钟频率 = PCLK/({prescaler value + 1})/{divider value}
{prescaler value} = 1 to 255
{divider value} = 1, 2, 4, 8, 16
Dead Zone Length = 0 to 254
NOTE: If Dead Zone Length is set as "n", Real Dead Zone Length is "n + 1" (n = 0 to 254). Source clock of PCLK is BUS_DPLL in BLK_MIF
TCFG1
	Base Address: 0xC001_8000h (PWM)
	Address = Base Address + 0x04h, Reset Value = 0x0000_0000
Name 	Bit 	Type 	Description 	Reset Value
DIVIDER MUX2 	[11:8] 	RW	Select Mux input for PWM Timer 2
0000 = 1/1
0001 = 1/2
0010 = 1/4
0011 = 1/8
0100 = 1/16
0101 = External TCLK1
0110 = External TCLK1
0111 = External TCLK1	4'h0

TCON
	Base Address: 0xC001_8000h (PWM)
	Address = Base Address + 0x08h, Reset Value = 0x0000_0000
Name 	Bit 	Type 	Description 	Reset Value
TIMER 2 AUTO RELOAD
ON/OFF 	[15] 	RW 	0 = One 
1 = Interval Mode -Shot (Auto-Reload) 	1'b0
TIMER 2 OUTPUT
INVERTER ON/OFF 	[14] 	RW 	0 = Inverter Off 
1 = TOUT2 Inverter-On 	1'b0
TIMER 2 MANUAL
UPDATE 	[13] 	RW 	0 = No Operation 
1 = Update TCNTB2,TCMPB2 	1'b0
TIMER 2 START/STOP 	[12] 	RW 	0 = Stop
1 = Start Timer 2 	1'b0
TCNTB2
	Base Address: 0xC001_8000h (PWM)
	Address = Base Address + 0x24h, Reset Value = 0x0000_0000
Name 	Bit 	Type 	Description 	Reset Value
TIMER 2 COUNT BUFFER 	[31:0] 	RW 	Timer 2 Count Buffer Register 	32'h0

TCMPB2
	Base Address: 0xC001_8000h (PWM)
	Address = Base Address + 0x28h, Reset Value = 0x0000_0000
Name 	Bit 	Type 	Description 	Reset Value
TIMER 2 COMPARE BUFFER 	[31:0] 	RW 	Timer 2 Compare Buffer Register 	32'h0

TCNTO2
	Base Address: 0xC001_8000h (PWM)
	Address = Base Address + 0x2Ch, Reset Value = 0x0000_0000
Name 	Bit 	Type 	Description 	Reset Value
TIMER 2 COUNT OBSERVATION 	[31:0] 	R 	Timer 2 Count Observation Register 	32'h0

七、实验代码
寄存器定义：
/*  
 *S5P6818 SFR address define
 *farsight
 *2017.10.1
 *version: 1.0
*/

#ifndef ___S5P6818_PWM_H_
#define ___S5P6818_PWM_H_

#define  	__REG(x)					(*(volatile unsigned int *)(x))  
#define    uint32                       unsigned int

/************* PWM ******************/
typedef struct {
	uint32 TCFG0;
	uint32 TCFG1;
	uint32 TCON;
	uint32 TCNTB0;
	uint32 TCMPB0;
	uint32 TCNTO0;
	uint32 TCNTB1;
	uint32 TCMPB1;
	uint32 TCNTO1;
	uint32 TCNTB2;
	uint32 TCMPB2;
	uint32 TCNTO2;
	uint32 TCNTB3;
	uint32 TCMPB3;
	uint32 TCNTO3;
	uint32 TCNTB4;
	uint32 TCNTO4;
	uint32 TINT_CSTAT;
}pwm;

#define PWM       (* (volatile pwm *)0xC0018000)
#endif

实验代码：
#include "s5p6818_PWM.h"

void Delay_Ms(unsigned int ms)
{
	unsigned int i,j;
	for (i = 0; i < ms; i++)
		for (j = 0; j < 2500; j++);
}

void PWM_Init(void)
{
	//有源蜂鸣器，直接让蜂鸣器发出声音
#if 0
	// 1. 设置GPIOC14引脚为GPIO功能
	GPIOC.ALTFN0 = GPIOC.ALTFN0 & (~(0x3 << 28)) | (0x1 << 28);
	// 2. 设置GPIOC14引脚为输出功能
	GPIOC.OUTENB = GPIOC.OUTENB | (0x1 << 14);
	// 3. 设置GPIOC14引脚输出高电平
	GPIOC.OUT = GPIOC.OUT | (0x1 << 14);

#else// 有原蜂鸣器，让蜂鸣器的声音发生变化，通过PWM调节蜂鸣器的声音
	// 1. 设置GPIOC14引脚为PWM功能
	GPIOC.ALTFN0 = GPIOC.ALTFN0 & (~(0x3 << 28)) | (0x2 << 28);
	// 2. 设置一级预分频值，设置PWM2通道，设置TCFG0[15:8]位，设置为249       f = 150M / (249+1) = 600000Hz
	PWM.TCFG0 = PWM.TCFG0 & (~(0xFF << 8)) | (249 << 8);
	// 3. 设置二级与分频值，设置TCFG1[11:8]位，设置为0100，进行16分频                       f = 600000Hz / 16 = 37500Hz
	PWM.TCFG1 = PWM.TCFG1 & (~(0xF << 8)) | (0x4 << 8);
	// 4. 设置PWM的终周期，设置TCNTB2， 设置为100     f = 37500Hz / 100 = 375;
	PWM.TCNTB2 = 100;
	// 5. 设置PWM的占空比，设置为50%， 设置为50
	PWM.TCMPB2 = 50;
	// 6. 打开手动加载
	PWM.TCON = PWM.TCON | (0x1 << 13);
	// 7. 关闭手动加载
	PWM.TCON = PWM.TCON & (~(0x1 << 13));
	// 8. 打开自动加载
	PWM.TCON = PWM.TCON | (0x1 << 15);
	// 9. 使能PWM定时器
	PWM.TCON = PWM.TCON | (0x1 << 12);
#endif

}

int main()
{
	printf("*******PWM test*********!\n");
	PWM_Init();

	while(1)
	{

	}
	return 0;
}