synchronous mode of usart(spi mode) in stm32 - c

Question

I am working with the following evaluation board: SZWB-sail, STM32f103VET6 KIT v3.1
I want to use the stm32f103 usart in synchronous mode, and I used
STM32F10x_StdPeriph_Lib_V3.5.0\Project\STM32F10x_StdPeriph_Examples\USART\Synchronous
I modified the code in an attempt to use USART2/SPI1, as opposed to the working code provided via STMicro, which uses USART1/SPI1.
The README for this example states that:
"USARTy and SPIy can be USART1 and SPI1 or USART2 and SPI3, depending on the STMicroelectronics EVAL board you are using."
Despite this, I attempted to physically connect USART2 Tx/Rx/Ck pins (PA2,PA3,PA4) to SPI1 SCK/MISO/MOSI (PA5,PA6,PA7). Is there a software reason for why this won't work? Or might it be hardware connections on the eval board?
Here is my code:
int main(void)
{
SystemInit();
Init_NVIC();
/* System Clocks Configuration */
RCC_Configuration();
/* Configure the GPIO ports */
GPIO_Configuration();
SPI_Configuration();
USART_Configuration();
while(NbrOfDataToRead2--)
{
USART2_Send_Byte(TxBuffer1[TxCounter1++]);
while(USART_GetFlagStatus(USART2, USART_FLAG_TC) == RESET)
{
}
while(SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_RXNE) == RESET)
{
}
RxBuffer2[RxCounter2++] = SPI_I2S_ReceiveData(SPI1);
}
USART2_Receive_Byte();
while(NbrOfDataToRead1--)
{
while(SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_TXE)== RESET)
{
}
SPI_I2S_SendData(SPI1, TxBuffer2[TxCounter2++]);
USART2_Send_Byte(DYMMY_BYTE);
while(USART_GetFlagStatus(USART2, USART_FLAG_TC) == RESET)
{
}
while(USART_GetFlagStatus(USART2, USART_FLAG_RXNE) == RESET)
{
}
RxBuffer1[RxCounter1++] = USART2_Receive_Byte();
}
TransferStatus1 = Buffercmp(TxBuffer1, RxBuffer2, TxBufferSize1);
TransferStatus2 = Buffercmp(TxBuffer2, RxBuffer1, TxBufferSize2);
while(1)
{
}
}
void Init_NVIC(void)
{
NVIC_InitTypeDef NVIC_InitStructure;
#ifdef VECT_TAB_RAM
NVIC_SetVectorTable(NVIC_VectTab_RAM, 0x0);
#else
NVIC_SetVectorTable(NVIC_VectTab_FLASH, 0x0);
#endif
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0);
NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}
void RCC_Configuration(void)
{
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA , ENABLE );
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1 , ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1 , ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2 , ENABLE);
}
void GPIO_Configuration(void)
{
GPIO_InitTypeDef GPIO_InitStructure1,GPIO_InitStructure2;
GPIO_InitTypeDef GPIO_InitStructure3,GPIO_InitStructure4,GPIO_InitStructure5,GPIO_InitStructure6;
/* Configure USART1 Rx as input floating */
GPIO_InitStructure1.GPIO_Pin =GPIO_Pin_10;
GPIO_InitStructure1.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure1.GPIO_Mode = GPIO_Mode_IN_FLOATING;
GPIO_Init(GPIOA, &GPIO_InitStructure1);
/* Configure USART1 Tx as alternate function push-pull */
GPIO_InitStructure2.GPIO_Pin =GPIO_Pin_9;
GPIO_InitStructure2.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure2.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_Init(GPIOA, &GPIO_InitStructure2);
/* Configure USART2 Rx as input floating */
GPIO_InitStructure3.GPIO_Pin =GPIO_Pin_3;
GPIO_InitStructure3.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure3.GPIO_Mode = GPIO_Mode_IN_FLOATING;
GPIO_Init(GPIOA, &GPIO_InitStructure3);
/* Configure USART2 Tx as alternate function push-pull */
GPIO_InitStructure4.GPIO_Pin =GPIO_Pin_2;
GPIO_InitStructure4.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure4.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_Init(GPIOA, &GPIO_InitStructure4);
/* Configure USART2 Ck as alternate function push-pull */
GPIO_InitStructure5.GPIO_Pin = GPIO_Pin_4;
GPIO_InitStructure5.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure5.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure5);
/* Configure SPI1 pins: SCK, MISO and MOSI */
GPIO_InitStructure6.GPIO_Pin = GPIO_Pin_5 | GPIO_Pin_6 | GPIO_Pin_7;
GPIO_Init(GPIOA, &GPIO_InitStructure6);
}
void USART_Configuration(void)
{
USART_InitTypeDef USART_InitStructure1,USART_InitStructure2;
USART_ClockInitTypeDef USART_ClkInitStructure;
USART_InitStructure1.USART_BaudRate = 115200;
USART_InitStructure1.USART_WordLength =USART_WordLength_8b ;
USART_InitStructure1.USART_StopBits = USART_StopBits_1;
USART_InitStructure1.USART_Parity = USART_Parity_No;
USART_InitStructure1.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
USART_InitStructure1.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
/* Configure USART1 */
USART_Init(USART1,&USART_InitStructure1);
//USART_ITConfig(USART1,USART_IT_RXNE,ENABLE);
/* Enable the USART1 */
USART_Cmd(USART1,ENABLE);
USART_ClkInitStructure.USART_Clock=USART_Clock_Enable;
USART_ClkInitStructure.USART_CPOL=USART_CPOL_High;
USART_ClkInitStructure.USART_CPHA=USART_CPHA_2Edge;
USART_ClkInitStructure.USART_LastBit=USART_LastBit_Enable;
USART_ClockInit(USART2, &USART_ClkInitStructure);
USART_InitStructure2.USART_BaudRate = 115200;
USART_InitStructure2.USART_WordLength =USART_WordLength_8b ;
USART_InitStructure2.USART_StopBits = USART_StopBits_1;
USART_InitStructure2.USART_Parity = USART_Parity_No;
USART_InitStructure2.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
USART_InitStructure2.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
/* Configure USART2 */
USART_Init(USART2,&USART_InitStructure2);
//USART_ITConfig(USART2,USART_IT_RXNE,ENABLE);
/* Enable the USART2 */
USART_Cmd(USART2,ENABLE);
}
void SPI_Configuration(void)
{
SPI_InitTypeDef SPI_InitStructure;
SPI_StructInit(&SPI_InitStructure);
SPI_I2S_DeInit(SPI1);
/* SPIy Config */
SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
SPI_InitStructure.SPI_Mode = SPI_Mode_Slave;
SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b;
SPI_InitStructure.SPI_CPOL = SPI_CPOL_High;
SPI_InitStructure.SPI_CPHA = SPI_CPHA_2Edge;
SPI_InitStructure.SPI_NSS = SPI_NSS_Soft;
SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_LSB;
/* Configure SPIy */
SPI_Init(SPI1, &SPI_InitStructure);
SPI_I2S_ITConfig(SPI1,SPI_I2S_IT_RXNE,ENABLE);
/* SPIy enable */
SPI_Cmd(SPI1, ENABLE);
}

Answer 1

You are mixing polling mode with interrupt mode. This SPI configuration code is intended for SPI interrupt mode. Hence, SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_RXNE) should not be used, because this is a function intended for Polling-Mode.
Instead, I believe you can use SPI_I2S_GetITStatus(SPI_TypeDef* SPIx, uint8_t SPI_I2S_IT); in conjunction with SPI_I2S_ReceiveData(SPI_TypeDef* SPIx) and SPI_I2S_ClearITPendingBit(SPI_TypeDef* SPIx, uint8_t SPI_I2S_IT) (to clear any potential Error pending bits, just in-case).
Also, you might want to post your USART2_Send_Byte() code so we know what exactly it's doing, and whether it's calling any other functions...but go ahead and try this first to see if it fixes your problem.

Answer 2

SPI1 conflicts with USART2 synchronization mode.
SPI2 conflicts with USART3 synchronization mode.
There is no conflict between SPI1/2 and USART1 synchronization modes.