airwill 发表于 2013-1-6 22:21 
我也感觉很可能延时计数的变量类型是不是小了, 比如用 unsigned char , 而定时长度却超过了 255, 导致永远 ...
我用的是long 整型，变量定义最够了，可是一旦超过350，就不行了，后来在官网里面的例程上改了，还是出现同样的问题，现在把修改官网的例程附上，延时参数改成350以下是正常的
/**
******************************************************************************
* @file GPIO_IOToggle/main.c
* @author MCD Application Team
* @version V1.1.0
* @date 20-September-2012
* @brief Main program body
******************************************************************************
* @attention
*
* <h2><center>© COPYRIGHT 2012 STMicroelectronics</center></h2>
*
* Licensed under MCD-ST Liberty SW License Agreement V2, (the "License");
* You may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.st.com/software_license_agreement_liberty_v2
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
******************************************************************************
*/
/* Includes ------------------------------------------------------------------*/
#include "main.h"
/** @addtogroup STM32F3_Discovery_Peripheral_Examples
* @{
*/
/** @addtogroup GPIO_IOToggle
* @{
*/
/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
#define BSRR_VAL 0xC000
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
GPIO_InitTypeDef GPIO_InitStructure;
/* Private function prototypes -----------------------------------------------*/
/* Private functions ---------------------------------------------------------*/
void Delay(__IO uint32_t nCount)
{
while (nCount != 0)
{
nCount--;
}
}
void Delay_Us(__IO uint32_t nCount)
{
while (nCount != 0)
{
nCount--;
Delay(150);
}
}
void Delay_Ms(__IO uint32_t nCount)
{
while (nCount != 0)
{
nCount--;
Delay(15000);
}
}
/**
* @brief Main program.
* @param None
* @retval None
*/
int main(void)
{
/*!< At this stage the microcontroller clock setting is already configured,
this is done through SystemInit() function which is called from startup
file (startup_stm32f30x.s) before to branch to application main.
To reconfigure the default setting of SystemInit() function, refer to
system_stm32f30x.c file
*/
/* GPIOE Periph clock enable */
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOE, ENABLE);
/* Configure PE14 and PE15 in output pushpull mode */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_15 | GPIO_Pin_14;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOE, &GPIO_InitStructure);
/* To achieve GPIO toggling maximum frequency, the following sequence is mandatory.
You can monitor PE14 and PE15 on the scope to measure the output signal.
If you need to fine tune this frequency, you can add more GPIO set/reset
cycles to minimize more the infinite loop timing.
This code needs to be compiled with high speed optimization option. */
while (1)
{
GPIO_SetBits( GPIOE,GPIO_Pin_14 | GPIO_Pin_15);
Delay_Ms(500);
GPIO_ResetBits( GPIOE,GPIO_Pin_14 | GPIO_Pin_15);
Delay_Ms(500);
}
}
#ifdef USE_FULL_ASSERT
/**
* @brief 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
* @retval None
*/
void assert_failed(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
/**
* @}
*/
/**
* @}
*/
/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
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