本帖最后由 sin1111yi 于 2023-2-13 17:07 编辑

最近在用GD32E503玩一些小东西，设计的时候把PA0用作了TIMER1_CH0，PA1用作TIMER1_CH1，如下所示PA1因为只需要输出一个PWM波即可，所以没有用DMA，PA0上的TIMER1_CH0根据官方的文档的描述应该是DMA0_CH4
但是按照DMA0_CH4写完代码，发现还是没有输出，故去查阅了官方的例子中的TIMER/TIMER0_dma
得到了如下的配置代码

/*!
    \brief      configure the GPIO ports
    \param[in]  none
    \param[out] none
    \retval     none
*/
void gpio_config(void)
{
    rcu_periph_clock_enable(RCU_GPIOA);
    rcu_periph_clock_enable(RCU_AF);

    /*configure PA8(TIMER0 CH0) as alternate function*/
    gpio_init(GPIOA,GPIO_MODE_AF_PP,GPIO_OSPEED_50MHZ,GPIO_PIN_8);
}

/*!
    \brief      configure the DMA peripheral
    \param[in]  none
    \param[out] none
    \retval     none
*/
void dma_config(void)
{
    dma_parameter_struct dma_init_struct;

    /* enable DMA clock */
    rcu_periph_clock_enable(RCU_DMA0);

    /* initialize DMA channel5 */
    dma_deinit(DMA0,DMA_CH4);

    /* DMA channel5 initialize */
    dma_init_struct.periph_addr = (uint32_t)TIMER0_CH0CV;
    dma_init_struct.periph_inc = DMA_PERIPH_INCREASE_DISABLE;
    dma_init_struct.memory_addr = (uint32_t)buffer;
    dma_init_struct.memory_inc = DMA_MEMORY_INCREASE_ENABLE;
    dma_init_struct.periph_width = DMA_PERIPHERAL_WIDTH_16BIT;
    dma_init_struct.memory_width = DMA_MEMORY_WIDTH_16BIT;
    dma_init_struct.direction = DMA_MEMORY_TO_PERIPHERAL;
    dma_init_struct.number = 3;
    dma_init_struct.priority = DMA_PRIORITY_ULTRA_HIGH;
    dma_init(DMA0,DMA_CH4,&dma_init_struct);

    dma_circulation_enable(DMA0,DMA_CH4);

    /* enable DMA channel5 */
    dma_channel_enable(DMA0,DMA_CH4);
}

/*!
    \brief      configure the TIMER peripheral
    \param[in]  none
    \param[out] none
    \retval     none
*/
void timer_config(void)
{
    /* TIMER0 DMA Transfer example -------------------------------------------------
    TIMER0CLK = 180MHz, Prescaler = 179
    TIMER0 counter clock = systemcoreclock/180 = 1MHz.

    the objective is to configure TIMER0 channel 1 to generate PWM
    signal with a frequency equal to 1KHz and a variable duty cycle(25%,50%,75%) that is
    changed by the DMA after a specific number of update DMA request.

    the number of this repetitive requests is defined by the TIMER0 repetition counter,
    each 2 update requests, the TIMER0 Channel 0 duty cycle changes to the next new
    value defined by the buffer .
    -----------------------------------------------------------------------------*/
    timer_oc_parameter_struct timer_ocintpara;
    timer_parameter_struct timer_initpara;

    rcu_periph_clock_enable(RCU_TIMER0);

    timer_deinit(TIMER0);

    /* TIMER0 configuration */
    timer_initpara.prescaler         = 179;
    timer_initpara.alignedmode       = TIMER_COUNTER_EDGE;
    timer_initpara.counterdirection  = TIMER_COUNTER_UP;
    timer_initpara.period            = 999;
    timer_initpara.clockdivision     = TIMER_CKDIV_DIV1;
    timer_initpara.repetitioncounter = 1;
    timer_init(TIMER0,&timer_initpara);

    /* CH0 configuration in PWM1 mode */
    timer_ocintpara.outputstate  = TIMER_CCX_ENABLE;
    timer_ocintpara.outputnstate = TIMER_CCXN_DISABLE;
    timer_ocintpara.ocpolarity   = TIMER_OC_POLARITY_HIGH;
    timer_ocintpara.ocnpolarity  = TIMER_OCN_POLARITY_HIGH;
    timer_ocintpara.ocidlestate  = TIMER_OC_IDLE_STATE_HIGH;
    timer_ocintpara.ocnidlestate = TIMER_OCN_IDLE_STATE_LOW;
    timer_channel_output_config(TIMER0,TIMER_CH_0,&timer_ocintpara);

    timer_channel_output_pulse_value_config(TIMER0,TIMER_CH_0,buffer[0]);
    timer_channel_output_mode_config(TIMER0,TIMER_CH_0,TIMER_OC_MODE_PWM0);
    timer_channel_output_shadow_config(TIMER0,TIMER_CH_0,TIMER_OC_SHADOW_DISABLE);

    /* TIMER0 primary output enable */
    timer_primary_output_config(TIMER0,ENABLE);
    /* channel DMA request source selection */
    timer_channel_dma_request_source_select(TIMER0,TIMER_DMAREQUEST_UPDATEEVENT);
    /* configure the TIMER DMA transfer */
    timer_dma_transfer_config(TIMER0,TIMER_DMACFG_DMATA_CH0CV,TIMER_DMACFG_DMATC_1TRANSFER);
    /* TIMER0 update DMA request enable */
    timer_dma_enable(TIMER0,TIMER_DMA_UPD);

    /* auto-reload preload enable */
    timer_auto_reload_shadow_enable(TIMER0);

    /* TIMER0 counter enable */
    timer_enable(TIMER0);
}


可以看到官方的案例给PA8上的TIMER0_CH0配置的DMA是DMA0_CH4，又和官方手册里的描述不一致，但是下载改代码，确实可以检测到PA8的PWM输出和例子描述一致

请教各位大佬，不知道是我理解出错了，还是官方的文档或者代码有问题呢？