NuMicro M051™ 系 列 有 2 个 PWM 组 ， 支 持 4 组 PWM 发 生 器 ， 可 配 置 成 8 个 独 立 的 PWM 输 出 ,
PWM0~PWM7, 或 者4 个 互 补 的PWM对, (PWM0, PWM1), (PWM2, PWM3), (PWM4, PWM5) 和
(PWM6, PWM7) ，带4个可编程的死区发生器.
每组PWM发生器带有8位预分频器，一个时钟分频器提供5种分频(1, 1/2, 1/4, 1/8, 1/16), 两个PWM定时
器包括2个时钟选择器，两个16位PWM向下计数计数器用于PWM周期控制，两个16位比较器用于PWM
占空比控制以及一个死区发生器。 4组PWM发生器提供8个独立的PWM中断标志，这些中断标志当相应
的PWM周期向下计数器达到零时由硬件置位。每个PWM中断源和它相应的中断使能位可以引起CPU请
求PWM中断。 PWM发生器可以配置为单触发模式产生仅仅一个PWM周期或自动重载模式连续输出
PWM波形。
当PCR.DZEN01置位, PWM0 与 PWM1执行互补的PWM对功能，这一对PWM的时序，周期，占空比和
死区时间由PWM0定时器和死区发生器0决定。同样， PWM互补对(PWM2, PWM3)， (PWM4, PWM5)
与 (PWM6, PWM7) 分别由 PWM2， PWM4 与 PWM6 定时器和死区发生器2， 4， 6控制，参考下图查
看PWM定时器架构。
为防止PWM输出不稳定波形， 16位向下计数计数器和16位比较器采用双缓存器。当用户向计数器/比较
器缓冲寄存器内写入值，只有当向下计数计数器的值达到0时，被更新的值才会被装载到16位计数器/比
较器。该双缓冲特性避免PWM输出波形上产生毛刺。
当16位向下计数计数器达到0时，中断请求产生。如果PWM定时器被配置为自动重装载模式，当向下计
数器达到0时，会自动重新装载PWM计数器寄存器(CNRx)的值，并开始递减计数，如此连续重复。如
果定时器设为单触发模式，当向下计数器达到0时，向下计数器停止计数，并产生一个中断请求。
PWM计数器比较器的值用于高电平脉冲宽度调制，当向下计数器的值与比较寄存器的值相同时，计数
器控制逻辑改变输出为高电平。
PWM定时器可复用为数字输入捕捉功能。如果捕捉功能使能， PWM的输出引脚将被切换至捕捉输入模
式。捕捉器0和PWM0使用同一个定时器，捕捉器1和PWM1使用另一组定时器，以此类推。因此在使用
捕捉功能之前，用户必须预先配置PMW定时器。捕捉功能使能后，捕捉器在输入通道的上升沿将PWM
计数器值锁存至捕捉上升沿锁存寄存器(CRLR)，在输入通道的下降沿将PWM计数器值锁存至捕捉下降
沿锁存寄存器(CFLR)。捕捉通道0中断是可编程的，通过设定CCR0.CRL_IE0[1] (上升沿锁存中断使能)
和CCR0.CFL_IE0[2]] (下降沿锁存中断使能) 来决定中断发生的条件。 通过设置CCR0.CRL_IE1[17]和
CCR0.CRL_IE1[18]，捕捉通道1有同样的特性。通过设置相应的控制位，每组的通道0到通道3有同样
的特性。 对于每一组，不管捕捉何时产生中断0/1/2/3， PWM计数器0/1/2/3都将在该时刻重载。
最大的捕捉频率受捕捉中断延迟限制。捕捉中断发生时，软件至少要执行三个步骤：读PIIRx 以得到中
断源，读PWM_CRLx/PWM_CFLx(x=0到3) 以得到捕捉值，写1清PIIRx。 如果中断延迟要花时间T0完
成， 在这段时间内(T0)，捕捉信号一定不能翻转。在这种情况下，最大的捕捉频率将是1/T0。例如：
HCLK = 50 MHz, PWM_CLK = 25 MHz, 中断延迟时间 900 ns
因此最大的捕捉频率将是1/900ns ≈ 1000 kHz
/**************************************************************************//**
* [url=home.php?mod=space&uid=288409]@file[/url] main.c
* [url=home.php?mod=space&uid=895143]@version[/url] V1.00
* $Revision: 3 $
* $Date: 14/01/28 11:44a $
* [url=home.php?mod=space&uid=247401]@brief[/url] M051 Series PWM Generator and Capture Timer Driver Sample Code
*
* @note
* Copyright (C) 2014 Nuvoton Technology Corp. All rights reserved.
*
******************************************************************************/
#include <stdio.h>
#include "M051Series.h"
/*---------------------------------------------------------------------------------------------------------*/
/* Macro, type and constant definitions */
/*---------------------------------------------------------------------------------------------------------*/
#define PLLCON_SETTING CLK_PLLCON_50MHz_HXT
#define PLL_CLOCK 50000000
// Scale frequency and unit is Hz
#define TENOR_C 523
#define TENOR_D 587
#define TENOR_E 659
#define TENOR_F 698
#define TENOR_G 784
#define TENOR_A 880
#define TENOR_B 988
void PWM_PwmIRQHandler(void);
/*---------------------------------------------------------------------------------------------------------*/
/* Global variables */
/*---------------------------------------------------------------------------------------------------------*/
volatile uint8_t g_u8PWMCount = 1;
volatile uint16_t g_u16Frequency;
volatile uint32_t g_u32Pulse = 0;
/* Assume PWM output frequency is 523Hz and duty ratio is 60%, user can calculate PWM settings by follows.
PWM clock source frequency = __HXT = 12000000 in the sample code.
(CNR+1) = PWM clock source frequency/prescaler/clock source divider/PWM output frequency
= 12000000/2/1/523 = 11472 < 65536 (Note: If calculated value is larger than 65536, user should increase prescale value.)
CNR = 11471 =>g_au16ScaleCnr[0] = 11471
duty ratio = 60% = (CMR+1)/(CNR+1) ==> CMR = (CNR+1)*60/100-1 = 11472*60/100-1
CMR = 6882 =>g_au16ScaleCmr[0] = 6882
*/
static const uint16_t g_au16ScaleFreq[7] = {TENOR_C, TENOR_D, TENOR_E, TENOR_F, TENOR_G, TENOR_A, TENOR_B};
// static const uint16_t g_au16ScaleCnr[7] = {11471,10220,9103,8594,7652,6817,6071};
// static const uint16_t g_au16ScaleCmr[7] = {6882 ,6131 ,5461,5156,4590,4089,3642};
/**
* @brief PWMA IRQ Handler
*
* @param None
*
* [url=home.php?mod=space&uid=266161]@return[/url] None
*
* [url=home.php?mod=space&uid=1543424]@Details[/url] ISR to handle PWMA interrupt event
*/
void PWMA_IRQHandler(void)
{
uint32_t u32PwmIntFlag;
/* Handle PWMA Timer function */
u32PwmIntFlag = PWMA->PIIR;
/* PWMB channel 0 PWM timer interrupt */
if(u32PwmIntFlag & PWM_PIIR_PWMIF0_Msk)
{
PWMA->PIIR = PWM_PIIR_PWMIF0_Msk;
PWM_PwmIRQHandler();
}
}
/*---------------------------------------------------------------------------------------------------------*/
/* PWM Timer function */
/*---------------------------------------------------------------------------------------------------------*/
void PWM_PwmIRQHandler(void)
{
if(g_u32Pulse == 1 * g_u16Frequency / 10)
{
/*--------------------------------------------------------------------------------------*/
/* Stop PWMA channel 0 Timer (Recommended procedure method 2) */
/* Set PWM Timer counter as 0, When interrupt request happen, disable PWM Timer */
/*--------------------------------------------------------------------------------------*/
PWMA->CNR0 = 0;
}
if(g_u32Pulse == 1 * g_u16Frequency / 10 + 1)
g_u8PWMCount = 0;
g_u32Pulse++;
}
void SYS_Init(void)
{
/*---------------------------------------------------------------------------------------------------------*/
/* Init System Clock */
/*---------------------------------------------------------------------------------------------------------*/
/* Enable Internal RC clock */
CLK_EnableXtalRC(CLK_PWRCON_OSC22M_EN_Msk);
/* Waiting for IRC22M clock ready */
CLK_WaitClockReady(CLK_CLKSTATUS_OSC22M_STB_Msk);
/* Switch HCLK clock source to Internal RC and HCLK source divide 1 */
CLK_SetHCLK(CLK_CLKSEL0_HCLK_S_HIRC, CLK_CLKDIV_HCLK(1));
/* Enable external 12MHz XTAL, internal 22.1184MHz */
CLK_EnableXtalRC(CLK_PWRCON_XTL12M_EN_Msk | CLK_PWRCON_OSC22M_EN_Msk);
/* Enable PLL and Set PLL frequency */
CLK_SetCoreClock(PLLCON_SETTING);
/* Waiting for clock ready */
CLK_WaitClockReady(CLK_CLKSTATUS_PLL_STB_Msk | CLK_CLKSTATUS_XTL12M_STB_Msk | CLK_CLKSTATUS_OSC22M_STB_Msk);
/* Switch HCLK clock source to PLL, STCLK to HCLK/2 */
CLK_SetHCLK(CLK_CLKSEL0_HCLK_S_PLL, CLK_CLKDIV_HCLK(2));
/* Enable UART module clock */
CLK_EnableModuleClock(UART0_MODULE);
/* Enable PWM module clock */
CLK_EnableModuleClock(PWM01_MODULE);
CLK_EnableModuleClock(PWM23_MODULE);
/* Select UART module clock source */
CLK_SetModuleClock(UART0_MODULE, CLK_CLKSEL1_UART_S_HXT, CLK_CLKDIV_UART(1));
/* Select PWM module clock source */
CLK_SetModuleClock(PWM01_MODULE, CLK_CLKSEL1_PWM01_S_HXT, 0);
CLK_SetModuleClock(PWM23_MODULE, CLK_CLKSEL1_PWM23_S_HXT, 0);
/* Reset PWMA channel0~channel3 */
SYS_ResetModule(PWM03_RST);
/* Update System Core Clock */
/* User can use SystemCoreClockUpdate() to calculate PllClock, SystemCoreClock and CycylesPerUs automatically. */
//SystemCoreClockUpdate();
PllClock = PLL_CLOCK; // PLL
SystemCoreClock = PLL_CLOCK / 1; // HCLK
CyclesPerUs = PLL_CLOCK / 1000000; // For SYS_SysTickDelay()
/*---------------------------------------------------------------------------------------------------------*/
/* Init I/O Multi-function */
/*---------------------------------------------------------------------------------------------------------*/
/* Set P3 multi-function pins for UART0 RXD and TXD */
SYS->P3_MFP = SYS_MFP_P30_RXD0 | SYS_MFP_P31_TXD0;
/* Set P4 multi-function pins for PWMA Channel0 */
SYS->P4_MFP = SYS_MFP_P40_PWM0;
}
void UART0_Init(void)
{
/*---------------------------------------------------------------------------------------------------------*/
/* Init UART */
/*---------------------------------------------------------------------------------------------------------*/
/* Configure UART0 and set UART0 Baudrate */
UART_Open(UART0, 115200);
}
/*---------------------------------------------------------------------------------------------------------*/
/* Main Function */
/*---------------------------------------------------------------------------------------------------------*/
int32_t main(void)
{
uint8_t u8Item, u8ItemOK;
/* Unlock protected registers */
SYS_UnlockReg();
/* Init System, IP clock and multi-function I/O */
SYS_Init();
/* Lock protected registers */
SYS_LockReg();
/* Init UART0 for printf */
UART0_Init();
printf("+------------------------------------------------------------------------+\n");
printf("| PWM Driver Sample Code |\n");
printf("| |\n");
printf("+------------------------------------------------------------------------+\n");
printf(" This sample code will use PWMA channel 0 to drive Buzzer\n");
printf(" I/O configuration:\n");
printf(" PWM0(P4.0 PWMA channel 0) <--> Buzzer\n");
printf("\nPWM Timer Waveform Test. Waveform output(P4.0 PWMA channel 0) to Buzzer\n");
/* P4.0 PWMA channel 0 generates PWM frequency Do - Si */
printf("Select Test Item\n");
printf(" 1: Do (523Hz)Tenor C\n");
printf(" 2: Re (587Hz)\n");
printf(" 3: Mi (659Hz)\n");
printf(" 4: Fa (698Hz)\n");
printf(" 5: Sol(784Hz)\n");
printf(" 6: La (880Hz)\n");
printf(" 7: Si (988Hz)\n");
while(1)
{
u8ItemOK = 1;
u8Item = getchar();
printf("\t");
switch(u8Item)
{
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
g_u16Frequency = g_au16ScaleFreq[(u8Item - '1')];
break;
default:
u8ItemOK = 0;
break;
}
if(u8ItemOK)
{
g_u32Pulse = 0;
g_u8PWMCount = 1;
/* Assume PWM output frequency is 523Hz and duty ratio is 60%, user can calculate PWM settings by follows.
duty ratio = (CMR+1)/(CNR+1)
cycle time = CNR+1
High level = CMR+1
PWM clock source frequency = __HXT = 12000000
(CNR+1) = PWM clock source frequency/prescaler/clock source divider/PWM output frequency
= 12000000/2/1/523 = 11472
(Note: CNR is 16 bits, so if calculated value is larger than 65536, user should increase prescale value.)
CNR = 11471
duty ratio = 60% ==> (CMR+1)/(CNR+1) = 60% ==> CMR = (CNR+1)*0.6-1 = 11472*60/100-1
CMR = 6882
Prescale value is 1 : prescaler = 2
Clock divider is PWM_CSR_DIV1 : clock divider = 1
*/
/* Enable PWM Output pin */
PWM_EnableOutput(PWMA, 0x1);
PWM_ConfigOutputChannel(PWMA, PWM_CH0, g_u16Frequency, 60);
/* Enable Timer period Interrupt */
PWM_EnablePeriodInt(PWMA, PWM_CH0, PWM_PERIOD_INT_UNDERFLOW);
/* Enable PWMB NVIC */
NVIC_EnableIRQ((IRQn_Type)(PWMA_IRQn));
/* Enable PWM Timer */
PWM_Start(PWMA, 0x1);
while(g_u8PWMCount);
/*--------------------------------------------------------------------------------------*/
/* Stop PWM Timer (Recommended procedure method 2) */
/* Set PWM Timer counter as 0, When interrupt request happen, disable PWM Timer */
/* Set PWM Timer counter as 0 in Call back function */
/*--------------------------------------------------------------------------------------*/
/* Disable PWMB NVIC */
NVIC_DisableIRQ((IRQn_Type)(PWMA_IRQn));
/* Wait until PWMB channel 0 Timer Stop */
while(PWMA->PDR0 != 0);
/* Disable the PWM Timer */
PWM_Stop(PWMA, 0x1);
/* Disable PWM Output pin */
PWM_DisableOutput(PWMA, 0x1);
}
}
}
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