AT32F415 PWM 设置rt_pwm_set后必须调用rt_pwm_enable

我在使用AT32F415的PWM Demo时候必须在每次调用完rt_pwm_set后调用rt_pwm_enablePWM才能生效。
Demo代码如下

/*
 * Copyright (c) 2006-2022, RT-Thread Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date           Author       Notes
 * 2018-11-25     misonyo      first implementation.
 */
/*
 * 程序清单：这是一个 PWM 设备使用例程
 * 例程导出了 pwm_led_sample 命令到控制终端
 * 命令调用格式：pwm_led_sample
 * 程序功能：通过 PWM 设备控制 LED 灯的亮度，可以看到LED不停的由暗变到亮，然后又从亮变到暗。
*/

#include <rtthread.h>
#include <rtdevice.h>

#define PWM_DEV_NAME        "pwm1"  /* PWM设备名称 */
#define PWM_DEV_CHANNEL     1       /* PWM通道 */

struct rt_device_pwm *pwm_dev;      /* PWM设备句柄 */

static int pwm_led_sample(int argc, char *argv[])
{
    rt_uint32_t period, pulse, dir;

    period = 50000;    /* 周期为0.5ms，单位为纳秒ns */
    dir = 1;            /* PWM脉冲宽度值的增减方向 */
    pulse = 10000;          /* PWM脉冲宽度值，单位为纳秒ns */

    /* 查找设备 */
    pwm_dev = (struct rt_device_pwm *)rt_device_find(PWM_DEV_NAME);
    if (pwm_dev == RT_NULL)
    {
        rt_kprintf("pwm sample run failed! can't find %s device!\n", PWM_DEV_NAME);
        return RT_ERROR;
    }

    /* 设置PWM周期和脉冲宽度默认值 */
    rt_pwm_set(pwm_dev, PWM_DEV_CHANNEL, period, pulse);
    /* 使能设备 */
    rt_pwm_enable(pwm_dev, PWM_DEV_CHANNEL);

    while (1)
    {
        rt_thread_mdelay(50);
        if (dir)
        {
            pulse += 5000;      /* 从0值开始每次增加5000ns */
        }
        else
        {
            pulse -= 5000;      /* 从最大值开始每次减少5000ns */
        }
        if (pulse >= period)
        {
            dir = 0;
        }
        if (0 == pulse)
        {
            dir = 1;
        }

        /* 设置PWM周期和脉冲宽度 */
        rt_pwm_set(pwm_dev, PWM_DEV_CHANNEL, period, pulse);
//        rt_pwm_enable(pwm_dev, PWM_DEV_CHANNEL);
    }
}
/* 导出到 msh 命令列表中 */
MSH_CMD_EXPORT(pwm_led_sample, pwm sample);

Start by tracing the AT32F415 PWM implementation behind rt_pwm_set and rt_pwm_enable, using the PWM demo code in this report as the reproduction case. Verify whether changing the pulse after enabling should update the output without another enable call, and define done as consistent behavior with the documented PWM API and a confirmed reproduction result.