[National Technology Automotive MCU N32A455 Development Board] PWM square wave generation test

一个秋天

[National Technology Automotive MCU N32A455 Development Board] PWM square wave generation test [Copy link]

This week, we tested the PWM generation of N32A455. First, the connection wiring diagram is as follows:

The oscilloscope used is PicoScope 3205. Use a computer to view the waveform. Use the probe clip to clamp the probe on PA6, connect the ground to the GND of the board, and then download the following code to the board:

#include "main.h"

TIM_TimeBaseInitType TIM_TimeBaseStructure;
OCInitType TIM_OCInitStructure;
uint16_t CCR1_Val       = 333;
uint16_t CCR2_Val       = 249;
uint16_t CCR3_Val       = 166;
uint16_t CCR4_Val       = 83;
uint16_t PrescalerValue = 0;

void RCC_Configuration(void);
void GPIO_Configuration(void);


int main(void)
{
    RCC_Configuration();


    GPIO_Configuration();

    

    PrescalerValue = (uint16_t)(SystemCoreClock / 24000000) - 1;

    TIM_InitTimBaseStruct(&TIM_TimeBaseStructure);
    TIM_TimeBaseStructure.Period    = 665;
    TIM_TimeBaseStructure.Prescaler = PrescalerValue;
    TIM_TimeBaseStructure.ClkDiv    = 0;
    TIM_TimeBaseStructure.CntMode   = TIM_CNT_MODE_UP;

    TIM_InitTimeBase(TIM3, &TIM_TimeBaseStructure);


    TIM_InitOcStruct(&TIM_OCInitStructure);
    TIM_OCInitStructure.OcMode      = TIM_OCMODE_PWM1;
    TIM_OCInitStructure.OutputState = TIM_OUTPUT_STATE_ENABLE;
    TIM_OCInitStructure.Pulse       = CCR1_Val;
    TIM_OCInitStructure.OcPolarity  = TIM_OC_POLARITY_HIGH;

    TIM_InitOc1(TIM3, &TIM_OCInitStructure);

    TIM_ConfigOc1Preload(TIM3, TIM_OC_PRE_LOAD_ENABLE);

    TIM_OCInitStructure.OutputState = TIM_OUTPUT_STATE_ENABLE;
    TIM_OCInitStructure.Pulse       = CCR2_Val;

    TIM_InitOc2(TIM3, &TIM_OCInitStructure);

    TIM_ConfigOc2Preload(TIM3, TIM_OC_PRE_LOAD_ENABLE);

    TIM_OCInitStructure.OutputState = TIM_OUTPUT_STATE_ENABLE;
    TIM_OCInitStructure.Pulse       = CCR3_Val;

    TIM_InitOc3(TIM3, &TIM_OCInitStructure);

    TIM_ConfigOc3Preload(TIM3, TIM_OC_PRE_LOAD_ENABLE);


    TIM_OCInitStructure.OutputState = TIM_OUTPUT_STATE_ENABLE;
    TIM_OCInitStructure.Pulse       = CCR4_Val;

    TIM_InitOc4(TIM3, &TIM_OCInitStructure);

    TIM_ConfigOc4Preload(TIM3, TIM_OC_PRE_LOAD_ENABLE);

    TIM_ConfigArPreload(TIM3, ENABLE);

    TIM_Enable(TIM3, ENABLE);

    while (1)
    {
    }
}


void RCC_Configuration(void)
{
    RCC_EnableAPB1PeriphClk(RCC_APB1_PERIPH_TIM3, ENABLE);

    RCC_EnableAPB2PeriphClk(
        RCC_APB2_PERIPH_GPIOA | RCC_APB2_PERIPH_GPIOB | RCC_APB2_PERIPH_GPIOC | RCC_APB2_PERIPH_AFIO, ENABLE);
}


void GPIO_Configuration(void)
{
    GPIO_InitType GPIO_InitStructure;

    /* GPIOA Configuration:TIM3 Channel1, 2, 3 and 4 as alternate function push-pull */
    GPIO_InitStruct(&GPIO_InitStructure);
    GPIO_InitStructure.Pin        = GPIO_PIN_6 | GPIO_PIN_7;
    GPIO_InitStructure.GPIO_Mode  = GPIO_Mode_AF_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

    GPIO_InitPeripheral(GPIOA, &GPIO_InitStructure);

    GPIO_InitStructure.Pin = GPIO_PIN_0 | GPIO_PIN_1;
    GPIO_InitPeripheral(GPIOB, &GPIO_InitStructure);
}

#ifdef USE_FULL_ASSERT


void assert_failed(const uint8_t* expr, const uint8_t* file, uint32_t line)
{
   

    while (1)
    {
    }
}

#endif

This setting sets the PWM clock to 72MHz, PA6 duty cycle to 50%, PA7 duty cycle to 37.5%, PB0 duty cycle to 25%, and PB1 duty cycle to 12.5%. The corresponding waveforms are as follows:

PA6:

PA7:

PB0:

PB1:

It can be seen that the PWM waveform is output according to the corresponding duty cycle. The test process is relatively smooth.