Interfacing with External SPI Flash Memory M25P40

[Fede Rico]

Posted on November 16, 2017 at 16:09

Hello,

I'm tring to read and write data from a SPI Flash Memory M25P40 with an STM32F103VDT

As first try, I started to read the flash memory serial number.

I used Cube32Mx to generate the initialization code.

This is the SPI3 initialisation function:

static void MX_SPI3_Init(void)
{
 hspi3.Instance = SPI3;
 hspi3.Init.Mode = SPI_MODE_MASTER;
 hspi3.Init.Direction = SPI_DIRECTION_2LINES;
 hspi3.Init.DataSize = SPI_DATASIZE_8BIT;
 hspi3.Init.CLKPolarity = SPI_POLARITY_LOW;
 hspi3.Init.CLKPhase = SPI_PHASE_1EDGE;
 hspi3.Init.NSS = SPI_NSS_HARD_OUTPUT;
 hspi3.Init.BaudRatePrescaler = SPI_BAUDRATEPRESCALER_8;
 hspi3.Init.FirstBit = SPI_FIRSTBIT_MSB;
 hspi3.Init.TIMode = SPI_TIMODE_DISABLE;
 hspi3.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLE;
 hspi3.Init.CRCPolynomial = 10;
 if (HAL_SPI_Init(&hspi3) != HAL_OK)
 {
 _Error_Handler(__FILE__, __LINE__);
 }
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I configure the SPI to use the Interrupt and this is my SPI code:

uint8_t SPI_Read( SPI_Channel_t channel, uint8_t* buffer, uint16_t bufferSize, uint32_t timeout )
{
 uint8_t opResult;
 opResult = ( HAL_SPI_Receive_IT( SPI_Handlers[channel], buffer, bufferSize ) == HAL_OK ) ? TRUE : FALSE;
 opResult &= (osSemaphoreWait( SPI_RX_SemaphoreId[channel], timeout ) == osOK ? TRUE : FALSE );
 return opResult;
}

uint8_t SPI_Write( SPI_Channel_t channel, uint8_t* buffer, uint16_t bufferSize, uint32_t timeout )
{
 uint8_t opResult;
 
 opResult = ( HAL_SPI_Transmit_IT(SPI_Handlers[channel], buffer, bufferSize) == HAL_OK ) ? TRUE : FALSE;
 opResult &= ( osSemaphoreWait( SPI_TX_SemaphoreId[channel], timeout ) == osOK ? TRUE : FALSE );
 
 return opResult;
}
uint8_t SPI_WriteRead( SPI_Channel_t channel, uint8_t* bufferIn, OUT uint8_t* bufferOut, uint16_t bufferSize, uint32_t timeout )
{
 uint8_t opResult;
 
 opResult = ( HAL_SPI_TransmitReceive_IT(SPI_Handlers[channel], bufferIn, bufferOut, bufferSize) == HAL_OK ) ? TRUE : FALSE;
 opResult &= ( osSemaphoreWait( SPI_TXRX_SemaphoreId[channel], timeout ) == HAL_OK ? TRUE : FALSE );
 
 return opResult;
}
/*========== Interrupt callback ==========*/
void HAL_SPI_TxCpltCallback(SPI_HandleTypeDef *hspi)
{
 SPI_Channel_t channel;
 
 if( hspi == SPI_Handlers[SPI_BLUETOOTH] ) { channel = SPI_BLUETOOTH; }
 else if( hspi == SPI_Handlers[SPI_EFLASH] ) { channel = SPI_EFLASH; }
 else
 {
 /* TODO: error */ 
 LOG_Print( LOG_SOURCE_SPI, LOG_LEVEL_ERROR, ''[SPI] Tx cb unknown channel''); 
 return;
 }
 osSemaphoreRelease( SPI_TX_SemaphoreId[channel] );
}

void HAL_SPI_RxCpltCallback(SPI_HandleTypeDef *hspi)
{
 SPI_Channel_t channel;
 
 if( hspi == SPI_Handlers[SPI_BLUETOOTH] ) { channel = SPI_BLUETOOTH; }
 else if( hspi == SPI_Handlers[SPI_EFLASH] ) { channel = SPI_EFLASH; }
 else
 {
 /* TODO: error */ 
 LOG_Print( LOG_SOURCE_SPI, LOG_LEVEL_ERROR, ''[SPI] Rx cb unknown channel'');
 return;
 }
 osSemaphoreRelease( SPI_RX_SemaphoreId[channel] );
}

void HAL_SPI_TxRxCpltCallback(SPI_HandleTypeDef *hspi)
{
 SPI_Channel_t channel;
 
 if( hspi == SPI_Handlers[SPI_BLUETOOTH] ) { channel = SPI_BLUETOOTH; }
 else if( hspi == SPI_Handlers[SPI_EFLASH] ) { channel = SPI_EFLASH; }
 else
 {
 /* TODO: error */ 
 LOG_Print( LOG_SOURCE_SPI, LOG_LEVEL_ERROR, ''[SPI] TxRx cb unknown channel'');
 return;
 }
 osSemaphoreRelease( SPI_TXRX_SemaphoreId[channel]);
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As you can see in the above code, the semaphore is released by the Tx/Rx/TxRx interrupt.

When I try to perform a simple serial number read, the Rx Interrupt is not raised.

This is the code to read the flash memory serial number:

opResult = SPI_Write( SPI_EFLASH, 0x9F, 1, EFLASH_WRITE_COMMAND_TIMEOUT );
/* The serial number has 20 bytes */
opResult = SPI_Read( SPI_EFLASH, buffer, 20, EFLASH_READ_COMMAND_TIMEOUT );�?�?�?�?

Unfortunately, the read operation fails dut to semaphore timeout. This happens because the Rx interrupt is not raised.

I also the SPI communication with a logic analyzer and the serial number bytes are exchanged on the SPI ad you can see in the below image:

Any suggestion?

I checked everything... But maybe I forget something.

Thanks!

#spi-write-and-read #flash-memory #stm32f1-spi