98 lines
3.3 KiB
Plaintext
98 lines
3.3 KiB
Plaintext
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4.1 测试
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使用STC32G12K128开发板进行PWM测试：
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在无晶振情况下，测试PWM输出400HZ，50HZ频率PWM波，误差均小于0.02%
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使用引脚：P6.0
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代码如下：
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#include "stc32g.h"
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#include "intrins.h"
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#define MAIN_Fosc 24000000L // 主时钟24MHz
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typedef unsigned char u8;
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typedef unsigned int u16;
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typedef unsigned long u32;
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/**************************** 固定参数 400Hz PWM ****************************/
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//#define PWM_FREQ 400 // 目标频率
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//#define PERIOD 59999 // 24MHz下 400Hz 对应周期值
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//#define DUTY 18000 // 30%占空比 (PERIOD/2)
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/**************************** 正确参数：50Hz / 30%占空比 ****************************/
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#define PWM_FREQ 50
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#define PSC_VAL 239 // 预分频值（核心修复：解决16位溢出）
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#define PERIOD 1999 // 周期值（16位寄存器最大值65535，合规）
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#define DUTY 600 // 30%占空比 (1999*0.3=600)
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/**************************** 官方宏定义 保留 ****************************/
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#define PWM1_0 0x00 //P:P1.0 N:P1.1
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#define PWM1_1 0x01 //P:P2.0 N:P2.1
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#define PWM1_2 0x02 //P:P6.0 N:P6.1 ? 最终输出引脚
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#define ENO1P 0x01
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/*****************************************************************************/
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void UpdatePwm(void);
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/******************** 主函数 **************************/
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void main(void)
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{
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WTST = 0;
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EAXFR = 1; // 扩展寄存器访问使能
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CKCON = 0;
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// IO口初始化
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P0M1 = 0x00; P0M0 = 0x00;
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P1M1 = 0x00; P1M0 = 0x00;
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P2M1 = 0x00; P2M0 = 0x00;
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P3M1 = 0x00; P3M0 = 0x00;
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P4M1 = 0x00; P4M0 = 0x00;
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P5M1 = 0x00; P5M0 = 0x00;
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P6M1 = 0x00; P6M0 = 0x00;
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P7M1 = 0x00; P7M0 = 0x00;
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// ===================== PWM 硬件配置 =====================
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PWMA_ENO = 0x00;
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PWMA_ENO |= ENO1P; // 使能PWM1通道输出
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PWMA_CCER1 = 0x00;
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PWMA_CCMR1 = 0x68; // PWM模式1输出
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PWMA_CCER1 = 0x01; // 高电平有效（正常输出）
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PWMA_PS = 0x00;
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PWMA_PS |= PWM1_2; // ? 选择通道：P6.0 输出
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// ========== 核心修复：配置预分频器（之前缺失！） ==========
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PWMA_PSCRH = (u8)(PSC_VAL >> 8);
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PWMA_PSCRL = (u8)PSC_VAL;
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UpdatePwm(); // 加载400Hz/50%占空比参数
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PWMA_BKR = 0x80; // 使能主输出（必备）
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PWMA_CR1 = 0x81; // 关键：关闭单脉冲模式 → 连续输出PWM
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EA = 1; // 开总中断（保留框架）
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while (1)
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{
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// 无需任何操作，硬件连续输出400Hz PWM
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}
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}
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//========================================================================
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// 函数: UpdatePwm(void)
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// 功能: 固定配置 400Hz + 50%占空比
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//========================================================================
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void UpdatePwm(void)
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{
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// 固定周期：59999 → 400Hz
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PWMA_ARRH = (u8)(PERIOD >> 8);
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PWMA_ARRL = (u8)PERIOD;
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// 固定占空比：29999 → 50%
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PWMA_CCR1H = (u8)(DUTY >> 8);
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PWMA_CCR1L = (u8)DUTY;
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}
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#################################################################################
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后面接上11.0592Mhz外部晶振，再测试PWM没有成功，在代码中对占空比进行调整均始终输出3.3V，PWM频率没有使用示波器测量
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由于时间原因，外部晶振策略搁置
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