How to ensure the SPI command always goes through in RTOS
Posted: Thu Nov 04, 2021 6:06 am
Hello. I have been learning RTOS and ESP32 for a while now. I have written my own flash memory drivers but I have got some concerns.
This is my write to flash memory function:
My concern is, that sometimes when I call these commands back to back, the flash chip is busy (the flag in status register is not clear and the flash chip is not ready to receive another command).
For example:
What is the best way to ensure that all called commands are executed? Is it appropriate to create RTOS task to handle all the flash memory functions? How can I use this task to perform all operations - write/erase/read?
This is my write to flash memory function:
Code: Select all
bool FLASH_write_page(spi_device_handle_t spi, int16_t pages, uint8_t* buf,uint8_t size)
{
esp_err_t ret;
spi_transaction_t SPITransaction;
if(FLASH_check_if_write_enabled(external_flash)==false){ // returns true if write is already enabled
FLASH_write_enable(external_flash);
}
if(FLASH_check_if_busy(spi) == true){ // return true if flash is not busy
memset(&SPITransaction, 0, sizeof(SPITransaction)); //Zero out the transaction
uint8_t command_byte = 0x02;
uint32_t addr = pages * 256; // page size is 256 bytes
SPITransaction.cmd=command_byte;
SPITransaction.addr=addr;
SPITransaction.tx_buffer = buf;
SPITransaction.length = 8*size;
ret = spi_device_polling_transmit(spi, &SPITransaction);
assert(ret==ESP_OK);
return 1;
}
return 0;
}
For example:
Code: Select all
FLASH_write_page(spi,1,data,sizeof(data)); will work because it is the first command
FLASH_write_page(spi,2,data,sizeof(data));// is likely to fail because the flash chip is busy from the first command
FLASH_write_page(spi,3,data,sizeof(data)); // this is likely to sucess because the MCU had enough time to clear the flag.
What is the best way to ensure that all called commands are executed? Is it appropriate to create RTOS task to handle all the flash memory functions? How can I use this task to perform all operations - write/erase/read?
