国民MCU最具有性价比的N32G430开发板：开发板自带下载器，所有GPIO引出，可以做芯片所有功能测评。 本次测评主要是基础时钟分析，串口配置，printf打印函数使用，
芯片介绍：
― ―32 位 ARM Cortex-M4 内核+ FPU，支持 DSP 指令和 MPU
― ― 内置 1KB 指令 Cache 缓存，支持 Flash 加速单元执行程序 0 等待
― ― 最高主频 128MHz，160DMIPS
时钟树：
下面进行时钟测试：
上代码:
#include <stdio.h>
#include "main.h"
USART_InitType USART_InitStructure;
void delay_us(uint32_t delay_us)
{
volatile unsigned int num;
volatile unsigned int t;
for (num = 0; num < delay_us; num++)
{
t = 11;
while (t != 0)
{
t--;
}
}
}
void delay_ms(uint16_t delay_ms)
{
volatile unsigned int num;
for (num = 0; num < delay_ms; num++)
{
delay_us(1000);
}
}
int main(void)
{
RCC_ClocksType RCC_ClocksStatus;
/* System Clocks Configuration */
RCC_Configuration();
/* Configure the GPIO ports */
GPIO_Configuration();
RCC_Clocks_Frequencies_Value_Get(&RCC_ClocksStatus);
/* USARTy and USARTz configuration ------------------------------------------------------*/
USART_InitStructure.BaudRate = 115200;
USART_InitStructure.WordLength = USART_WL_8B;
USART_InitStructure.StopBits = USART_STPB_1;
USART_InitStructure.Parity = USART_PE_NO;
USART_InitStructure.HardwareFlowControl = USART_HFCTRL_NONE;
USART_InitStructure.Mode = USART_MODE_RX | USART_MODE_TX;
/* Configure USARTx */
USART_Initializes(USARTx, &USART_InitStructure);
/* Enable the USARTx */
USART_Enable(USARTx);
/* Output a message on Hyperterminal using printf function */
// printf("\n\rUSART Printf Example: retarget the C library printf function to the USART\n\r");
while (1)
{
printf("SysclkFreq_Frequency %d \r\n",RCC_ClocksStatus.SysclkFreq);
printf("HclkFreq_Frequency %d \r\n",RCC_ClocksStatus.HclkFreq);
printf("Pclk1Freq_Frequency %d \r\n",RCC_ClocksStatus.Pclk1Freq);
printf("Pclk2Freq_Frequency %d \r\n",RCC_ClocksStatus.Pclk2Freq);
printf("AdcPllClkFreq_Frequency %d \r\n",RCC_ClocksStatus.AdcPllClkFreq);
printf("AdcHclkFreq_Frequency %d \r\n",RCC_ClocksStatus.AdcHclkFreq);
printf("\r\n"); printf("\r\n"); printf("\r\n");
delay_ms(5000);
}
}
/**
*\*\name RCC_Configuration.
*\*\fun Configures the different system clocks.
*\*\param none
*\*\return none
**/
void RCC_Configuration(void)
{
/* Enable GPIO clock */
GPIO_AHBClkCmd(USARTx_GPIO_CLK);
/* Enable USARTx Clock */
USART_APBxClkCmd(USARTx_CLK);
}
/**
*\*\name GPIO_Configuration.
*\*\fun Configures the different GPIO ports.
*\*\param none
*\*\return none
**/
void GPIO_Configuration(void)
{
GPIO_InitType GPIO_InitStructure;
/* Initialize GPIO_InitStructure */
GPIO_Structure_Initialize(&GPIO_InitStructure);
/* Configure USARTx Tx as alternate function push-pull */
GPIO_InitStructure.Pin = USARTx_TxPin;
GPIO_InitStructure.GPIO_Mode = GPIO_MODE_AF_PP;
GPIO_InitStructure.GPIO_Alternate = USARTx_Tx_GPIO_AF;
GPIO_Peripheral_Initialize(USARTx_GPIO, &GPIO_InitStructure);
/* Configure USARTx Rx as alternate function push-pull */
GPIO_InitStructure.Pin = USARTx_RxPin;
GPIO_InitStructure.GPIO_Alternate = USARTx_Rx_GPIO_AF;
GPIO_Peripheral_Initialize(USARTx_GPIO, &GPIO_InitStructure);
}
/**
*\*\name fputc.
*\*\fun retarget the C library printf function to the USART
*\*\param ch
*\*\param f
*\*\return none
**/
int fputc(int ch, FILE* f)
{
USART_Data_Send(USARTx, (uint8_t)ch);
while (USART_Flag_Status_Get(USARTx, USART_FLAG_TXDE) == RESET)
;
return (ch);
}
#ifdef USE_FULL_ASSERT
/**
*\*\name assert_failed.
*\*\fun Reports the name of the source file and the source line number
*\*\ where the assert_param error has occurred.
*\*\param file pointer to the source file name
*\*\param line assert_param error line source number
*\*\return none
**/
void assert_failed(const uint8_t* expr, const uint8_t* file, uint32_t line)
{
/* User can add his own implementation to report the file name and line number,
ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
/* Infinite loop */
while (1)
{
}
}
#endif
结构体：
typedef struct
{
uint32_t SysclkFreq; /* returns SYSCLK clock frequency expressed in Hz */
uint32_t HclkFreq; /* returns HCLK clock frequency expressed in Hz */
uint32_t Pclk1Freq; /* returns PCLK1 clock frequency expressed in Hz */
uint32_t Pclk2Freq; /* returns PCLK2 clock frequency expressed in Hz */
uint32_t AdcPllClkFreq; /* returns ADCPLLCLK clock frequency expressed in Hz */
uint32_t AdcHclkFreq; /* returns ADCHCLK clock frequency expressed in Hz */
} RCC_ClocksType;
keil下寄存器查看
打印测试：
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