Posted on August 16, 2016 at 14:20
If I removed the
Now it seems OK but why do I need this weird approach ?
Here is the SPI configuration data
Best Regards
Hi All
HAL_SPI_Receive
function has a strange problem, a simple workaround can be implemented as a temporal solution but I need reason of the this behaviour.
address = 0x138001;
// Ext_Flash_Write_Byte(address, 'A');
// Ext_Flash_Write_Byte(address+1, 'B');
// Ext_Flash_Write_Byte(address+2, 'C');
// Ext_Flash_Write_Byte(address+3, 'D');
// Ext_Flash_Write_Byte(address+4, 'E');
// Ext_Flash_Write_Byte(address+5, 'F');
// Ext_Flash_Write_Byte(address+6, 'G');
// Ext_Flash_Write_Byte(address+7, 'H');
// Ext_Flash_Write_Byte(address+8, 'I');
// Ext_Flash_Write_Byte(address+9, 'J');
data = Ext_Flash_Read_Byte(address+3);
Ext_Flash_Read(address, (uint8_t*)SPI_Rx_Buf, 10);10 capital letter
is written to External SPI flash memory and tried to read
one byte
and
ten bytes
to show the behaviour. Here is the read functions;
uint8_t Ext_Flash_Read_Byte(unsigned int address)
{
EXT_FLASH_CS_Low();
SPI_Tx_Buf[0] = CMD_READ;
SPI_Tx_Buf[1] = ((address >> 16) & 0xFF);
SPI_Tx_Buf[2] = ((address >> 8) & 0xFF);
SPI_Tx_Buf[3] = (address & 0xFF);
HAL_SPI_Transmit(&hspi1, (uint8_t*)SPI_Tx_Buf, 4, 100);
//HAL_SPI_Receive(&hspi1, (uint8_t*)SPI_Rx_Buf, 3, 100);
HAL_SPI_Receive(&hspi1, (uint8_t*)SPI_Rx_Buf, 1, 100);
EXT_FLASH_CS_High();
return SPI_Rx_Buf[0];
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
void Ext_Flash_Read(unsigned int address, uint8_t* pData, uint16_t n)
{
EXT_FLASH_CS_Low();
SPI_Tx_Buf[0] = CMD_READ;
SPI_Tx_Buf[1] = ((address >> 16) & 0xFF);
SPI_Tx_Buf[2] = ((address >> 8) & 0xFF);
SPI_Tx_Buf[3] = (address & 0xFF);
HAL_SPI_Transmit(&hspi1, (uint8_t*)SPI_Tx_Buf, 4, 100);
//HAL_SPI_Receive(&hspi1, (uint8_t*)SPI_Rx_Buf, 3, 100);
HAL_SPI_Receive(&hspi1, (uint8_t*)pData, n, 100);
EXT_FLASH_CS_High();
}Here is the result of these functions;
As you can see, single byte read has returned
0x00
instead of
'D'and multibyte array result has
shifted 3 bytes
and 1st byte is corrupted. BUT, logic analyzer shows that signal on the SPI bus seems as expected.
If I removed the
comments
on dummy 3 bytes read everything gets OK !functionHAL_SPI_Receive(&hspi1, (uint8_t*)SPI_Rx_Buf, 3, 100);
Adding 3 extra read sequence clocking bus for extra 3 bytes but it does not a problem for SPI flash, it just continue to out data by increasing its address. There is no any data except the written capital letters, so remaing 3 extra ouput data is 0xFF as expected.
Now it seems OK but why do I need this weird approach ?
Here is the SPI configuration data
Here is the SPI configuration code;
void MX_SPI1_Init(void)
{
hspi1.Instance = SPI1;
hspi1.Init.Mode = SPI_MODE_MASTER;
hspi1.Init.Direction = SPI_DIRECTION_2LINES;
hspi1.Init.DataSize = SPI_DATASIZE_8BIT;
hspi1.Init.CLKPolarity = SPI_POLARITY_LOW;
hspi1.Init.CLKPhase = SPI_PHASE_1EDGE;
hspi1.Init.NSS = SPI_NSS_SOFT;
hspi1.Init.BaudRatePrescaler = SPI_BAUDRATEPRESCALER_8;
hspi1.Init.FirstBit = SPI_FIRSTBIT_MSB;
hspi1.Init.TIMode = SPI_TIMODE_DISABLE;
hspi1.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLE;
hspi1.Init.CRCPolynomial = 7;
hspi1.Init.CRCLength = SPI_CRC_LENGTH_DATASIZE;
hspi1.Init.NSSPMode = SPI_NSS_PULSE_DISABLE;
if (HAL_SPI_Init(&hspi1) != HAL_OK)
Error_Handler();
}
void HAL_SPI_MspInit(SPI_HandleTypeDef* spiHandle)
{
GPIO_InitTypeDef GPIO_InitStruct;
if(spiHandle->Instance==SPI1)
{
__HAL_RCC_SPI1_CLK_ENABLE();
GPIO_InitStruct.Pin = GPIO_PIN_5|GPIO_PIN_6|GPIO_PIN_7;
GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
GPIO_InitStruct.Alternate = GPIO_AF0_SPI1;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
}
}What is the problem ?
Is there a problem in CubeMx function that handling SPI data packaging described below ? Or any point that I am missing ?
Best Regards
