STM32F439的奇怪问题?

long_wuyi 提问时间：2014-7-13 18:28 /

我在使用STM32F439IG芯片遇到怪问题,有请各位:
I2C初始代码如下:
我想
void I2C_Configuration(void)
{ I2C_InitTypeDef I2C_InitStructure;
GPIO_InitTypeDef GPIO_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C2,ENABLE);
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOH,ENABLE);
GPIO_PinAFConfig(GPIOH, GPIO_PinSource4, GPIO_AF_I2C2);
GPIO_PinAFConfig(GPIOH, GPIO_PinSource5, GPIO_AF_I2C2);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4 | GPIO_Pin_5;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_OType = GPIO_OType_OD;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOH, &GPIO_InitStructure);
I2C_SoftwareResetCmd(I2C2,ENABLE);
I2C_DeInit(I2C2);
I2C_SoftwareResetCmd(I2C2,DISABLE);
I2C_InitStructure.I2C_Mode = I2C_Mode_I2C;
I2C_InitStructure.I2C_DutyCycle = I2C_DutyCycle_2;
I2C_InitStructure.I2C_OwnAddress1 = 0x10;
I2C_InitStructure.I2C_Ack = I2C_Ack_Enable;
I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;
I2C_InitStructure.I2C_ClockSpeed = 400000;
I2C_Init(I2C2, &I2C_InitStructure);
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_InitStructure.NVIC_IRQChannel=I2C2_EV_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_Init(&NVIC_InitStructure);
NVIC_InitStructure.NVIC_IRQChannel = I2C2_ER_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_Init(&NVIC_InitStructure);
I2C_Cmd(I2C2, ENABLE);
}
本想加点中断处理,但只要在代码的任何地方加:
I2Cx->CR2|=I2C_IT_EVT|I2C_IT_ERR;
再编译下载后,执行I2C_Configuration都得到Busy=1的状态.
若将"I2Cx->CR2|=I2C_IT_EVT|I2C_IT_ERR",Busy=1的错误消失????