SPI主机中断接收

zhoutong

[mw_shl_code=c,true]void SPI1_Init(void) { GPIO_InitTypeDef GPIO_InitStructure; SPI_InitTypeDef SPI_InitStructure; RCC_APB2PeriphClockCmd( RCC_APB2Periph_GPIOA|RCC_APB2Periph_SPI1, ENABLE ); //configure MOSI(PA7) SCK(PA5) GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5 | GPIO_Pin_7; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //???????ì???? GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_Init(GPIOA, &GPIO_InitStructure); //configure MISO(PA6) GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING; //???????? GPIO_Init(GPIOA, &GPIO_InitStructure); /* Configure PA4 as CS */ GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP; GPIO_Init(GPIOA, &GPIO_InitStructure); SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex; //?è??SPI???ò?ò?????ò??????????:SPI?è???????????ò?????¤ SPI_InitStructure.SPI_Mode = SPI_Mode_Master; // Slave; // //?è??SPI?¤×÷????:?è?????÷SPI SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b; //?è??SPI???????ó??:SPI·???????8?????á?? SPI_InitStructure.SPI_CPOL = SPI_CPOL_Low; //???????®???±????????:?±???ü???? SPI_InitStructure.SPI_CPHA = SPI_CPHA_2Edge; //?????????????????±???? SPI_InitStructure.SPI_NSS = SPI_NSS_Soft; //NSS???????????¨NSS?????©?????í???¨????SSI???©???í:????NSS??????SSI?????? SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_64; //?¨???¨?????¤·???????:?¨?????¤·???????256 SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_LSB; //???¨??????????MSB??????LSB??????:??????????MSB?????? SPI_InitStructure.SPI_CRCPolynomial = 7; //CRC?????????à???? SPI_Init(SPI1, &SPI_InitStructure); //?ù??SPI_InitStruct?????¨???????????????èSPIx?????÷ SPI_I2S_ITConfig(SPI1, SPI_I2S_IT_RXNE, ENABLE); SPI_Cmd(SPI1, ENABLE); //????SPI???è //SPI1_ReadWriteByte(0xff); } void NVIC_Config(void) { NVIC_InitTypeDef NVIC_InitStructure; NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2); // NVIC_InitStructure.NVIC_IRQChannel = SPI1_IRQn; // NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=1; // NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1; // NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&NVIC_InitStructure); } void SPI_Select(void) { GPIO_ResetBits(GPIOA, GPIO_Pin_4); } void SPI_Release(void) { GPIO_SetBits(GPIOA, GPIO_Pin_4); } void delay(volatile uint32_t tick) { while(tick--); } //SPIx ????????×??? //TxData:????????×??? //·?????:????????×??? u8 SPI1_ReadWriteByte(u8 TxData) { while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_TXE) == RESET); //?ì?é???¨??SPI±ê?????è????·?:·?????????±ê???? SPI_I2S_SendData(SPI1, TxData); //?¨?????èSPIx·??????????? while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_RXNE) == RESET);//?ì?é???¨??SPI±ê?????è????·?:????????·???±ê???? return SPI_I2S_ReceiveData(SPI1); //·????¨??SPIx×??ü?????????? } u8 SPI1_Read() { while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_RXNE) == RESET);//?ì?é???¨??SPI±ê?????è????·?:????????·???±ê???? return SPI_I2S_ReceiveData(SPI1); //·????¨??SPIx×??ü?????????? } void SPI1_Write(u8 byte) { while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_TXE) == RESET); //?ì?é???¨??SPI±ê?????è????·?:·?????????±ê???? SPI_I2S_SendData(SPI1, byte); //?¨?????èSPIx·??????????? } void SPI1_IRQHandler(void) { if(SPI_I2S_GetITStatus(SPI1, SPI_I2S_IT_RXNE)!=RESET) { data=SPI1_Read(); } } int main() { USART1_INIT(); SPI1_Init(); SPI_Select(); NVIC_Config(); delay(0xFFFF); while(1) { SPI1_Write(0x55); } }[/mw_shl_code]

蓝色的是PA7（MOSI）脚信号，黄色的事PA6(MISO)信号。
在做SPI主机中断接收实验的时候发现：主机总是会循环进入接收中断，而我只是用单板测试，按道理应该是不会进入spi接收中断的啊！PA6脚是悬空的，为什么会有这样的波形的？请各位前辈帮我看看是什么原因，谢谢！

yangzhen86

SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
意味着发送的同时一定会接收中断，这是工作方式决定的，看一下SPI的工作方式和原理就明白了

zhoutong

回复【2楼】yangzhen86:
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明白了，谢谢啊！