用SPI1读写SPI EEPROM M95040. clock和MOSI都能正常工作，就是MISO上没有信号。用示波器看信号，MOSI信号符合时序。但是MISO上就是没有信号。
还有个很奇怪的问题。就是单步执行，发现能够写入，也能读出数量，任意修改写入某地址的数据，都能正确读出。但是全速运行时读出来的都是0xFF.是不是延时的问题？
程序如下：请高手看看。谢谢！
/* EEPROM instructions */
#define WREN 0x06
#define WRDI 0x04
#define RDSR 0x05
#define WRSR 0x01
#define READ 0x03
#define WRITE 0x02
/* Private variables ---------------------------------------------------------*/
SPI_InitTypeDef SPI_InitStructure;
/*-----------------------------------------------------------------------------
ROUTINE NAME : SPI_Init
INPUT/OUTPUT : None
DESCRIPTION : Configure the SPI peripheral
COMMENTS :
-----------------------------------------------------------------------------*/
void SPI_Config(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1 | RCC_APB2Periph_GPIOA|RCC_APB2Periph_AFIO, ENABLE);
/* Configure SPI1 pins: SCK, MISO and MOSI ---------------------------------*/
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4 ;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5 | GPIO_Pin_6 | GPIO_Pin_7;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_SetBits(GPIOA, GPIO_Pin_4);
/* SPI1 configuration */
SPI_I2S_DeInit(SPI1);
SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
SPI_InitStructure.SPI_Mode = SPI_Mode_Master;
SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b;
SPI_InitStructure.SPI_CPOL = SPI_CPOL_Low;
SPI_InitStructure.SPI_CPHA = SPI_CPHA_1Edge;
SPI_InitStructure.SPI_NSS = SPI_NSS_Soft;
SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_32;
SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
SPI_InitStructure.SPI_CRCPolynomial = 7;
SPI_Init(SPI1, &SPI_InitStructure);
/* Enable SPI1 */
SPI_Cmd(SPI1, ENABLE);
}
/*-----------------------------------------------------------------------------
ROUTINE NAME : Chk_WP_Bit
INPUT/OUTPUT : None/Boolean
DESCRIPTION : Return 'TRUE' if write is still in progress in the EEPROM (M95040)
COMMENTS :
-----------------------------------------------------------------------------*/
bool Chk_WP_Bit(void)
{
u8 i;
SPI_Cmd(SPI1, ENABLE);//SetBit(SPICR,6); // spi enable
GPIO_ResetBits(GPIOA,GPIO_Pin_4);
//SPI_SendByte(RDSR);
//SPI_SendByte(RDSR);
while((SPI1->SR & SPI_I2S_FLAG_TXE) == RESET);
SPI1->DR=RDSR;
while((SPI1->SR & SPI_I2S_FLAG_RXNE) == RESET);
i=SPI1->DR;
while((SPI1->SR & SPI_I2S_FLAG_TXE) == RESET);
SPI1->DR=RDSR;
while((SPI1->SR & SPI_I2S_FLAG_RXNE) == RESET);
i=SPI1->DR;
GPIO_SetBits(GPIOA,GPIO_Pin_4);//SetBit(PADR,6);
SPI_Cmd(SPI1, DISABLE);//ClrBit(SPICR,6); // spi disable
if(((SPI1->DR)|0xFE)==0xFE) return(TRUE);//(ValBit(SPIDR,0)) return(TRUE);
else
return(FALSE);
}
/*-----------------------------------------------------------------------------
ROUTINE NAME : Read_EEPROM
INPUT/OUTPUT : u8 (adress) / u8 (data)
DESCRIPTION : Return data located at the adress specified
COMMENTS :
-----------------------------------------------------------------------------*/
u8 Read_EEPROM(u8 add)
{
u8 data;
SPI_Cmd(SPI1, ENABLE);//SetBit(SPICR,6); // spi enable
GPIO_ResetBits(GPIOA,GPIO_Pin_4);
SPI_SendByte(READ);
SPI_SendByte(add);
data=SPI_ReadByte();
GPIO_SetBits(GPIOA,GPIO_Pin_4);
SPI_Cmd(SPI1, DISABLE);//ClrBit(SPICR,6); // spi disable
return (data);
}
/*-----------------------------------------------------------------------------
ROUTINE NAME : Send_EEPROM
INPUT/OUTPUT : u8,u8 (adress,data) / None
DESCRIPTION : Send data byte to the adress specified
COMMENTS :
-----------------------------------------------------------------------------*/
void Send_EEPROM(u8 add, u8 data)
{
SPI_Cmd(SPI1, ENABLE);//SetBit(SPICR,6); // spi enable
GPIO_ResetBits(GPIOA,GPIO_Pin_4);//ClrBit(PADR,6);
SPI_SendByte(WREN);
GPIO_SetBits(GPIOA,GPIO_Pin_4);//SetBit(PADR,6);
GPIO_ResetBits(GPIOA,GPIO_Pin_4);//ClrBit(PADR,6);
SPI_SendByte(WRITE);
SPI_SendByte(add);
SPI_SendByte(data);
GPIO_SetBits(GPIOA,GPIO_Pin_4);//SetBit(PADR,6);
SPI_Cmd(SPI1, DISABLE);//ClrBit(SPICR,6); // spi disable
}
/*******************************************************************************
* Function Name : SPI_SendByte
* Description : Sends a byte through the SPI interface and return the byte
* received from the SPI bus.
* Input : byte : byte to send.
* Output : None
* Return : The value of the received byte.
*******************************************************************************/
u8 SPI_SendByte(u8 byte)
{
/* Loop while DR register in not emplty */
while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_TXE) == RESET);
/* Send byte through the SPI1 peripheral */
SPI_I2S_SendData(SPI1, byte);
/* Wait to receive a byte */
while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_RXNE) == RESET);
/* Return the byte read from the SPI bus */
return SPI_I2S_ReceiveData(SPI1);
}
/*******************************************************************************
* Function Name : SPI_ReadByte
* Description : Reads a byte from the SPI Flash.
* This function must be used only if the Start_Read_Sequence
* function has been previously called.
* Input : None
* Output : None
* Return : Byte Read from the SPI Flash.
*******************************************************************************/
u8 SPI_ReadByte(void)
{
return (SPI_SendByte(0x55));
}
/*-----------------------------------------------------------------------------*/
void Delay_us(u16 us)
{
while(us--);
}
/*-----------------------------------------------------------------------------
ROUTINE NAME : Delay_ms
INPUT/OUTPUT : ms
DESCRIPTION :
COMMENTS :
-----------------------------------------------------------------------------*/
void Delay_ms(u16 ms)
{
u16 i,j;
for(i=0;i<ms;i++)
{
for(j=0;j<15;j++)
{
Delay_us(1);
}
}
} |
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