Flash Memory Issue

[Muqarrab]

Hi,
I have written these 3 functions to erase/read and write.

/////////////////////////////////////////////////////////////////////////////// SNV

const uint32_t f_addr = 0x000FF000; // Last page start address 255

// Create a pointer to that address
uint32_t * p_addr = (uint32_t *)f_addr; //cast f_addr to a pointer

uint32_t erase_SNV()
{
    NRF_LOG_INFO("Memory Erased");
    return sd_flash_page_erase(255);
}


uint32_t write_SNV(int address,uint8_t value)
{
    uint32_t val;
    val=value;
    NRF_LOG_INFO("Data Write in Flash");
    ret_code_t err_code;
    err_code = sd_flash_write(p_addr+address, &val, sizeof(val));
    APP_ERROR_CHECK(err_code);
    return err_code;
}

uint32_t read_SNV(int address)
{
     NRF_LOG_INFO("The Data read from flash is: %d", *(p_addr)+address);
     return *(p_addr)+address;
}

When I write any value from address 1 it gives following wrong output(0 1 2 3).

    write_SNV(1,11);
    read_SNV(1);
    write_SNV(2,12);
    read_SNV(2);
    write_SNV(3,13);
    read_SNV(3);

  //  read_SNV(0);
    read_SNV(1);
    read_SNV(2);
    read_SNV(3);

 



But When I start address from 0 it gives the right values.

    write_SNV(0,10);
    read_SNV(0);
    write_SNV(1,11);
    read_SNV(1);
    write_SNV(2,12);
    read_SNV(2);
    write_SNV(3,13);
    read_SNV(3);

    read_SNV(0);
    read_SNV(1);
    read_SNV(2);
    read_SNV(3);

How can I save values in rondom addresses?
Thanks!

[Edvin]

/**@brief   Function for erasing flash pages.
 *
 * @details This function erases @p len pages starting from the page at address @p page_addr.
 *          The erase operation must be initiated on a page boundary.
 *
 * @param[in]   p_fs        The fstorage instance.
 * @param[in]   page_addr   Address of the page to erase.
 * @param[in]   len         Number of pages to erase.
 * @param[in]   p_param     User-defined parameter passed to the event handler (may be NULL).
 *
 * @retval  NRF_SUCCESS                 If the operation was accepted.
 * @retval  NRF_ERROR_NULL              If @p p_fs is NULL.
 * @retval  NRF_ERROR_INVALID_STATE     If the module is not initialized.
 * @retval  NRF_ERROR_INVALID_LENGTH    If @p len is zero.
 * @retval  NRF_ERROR_INVALID_ADDR      If the address @p page_addr is outside the flash memory
 *                                      boundaries specified in @p p_fs, or if it is unaligned.
 * @retval  NRF_ERROR_NO_MEM            If no memory is available to accept the operation.
 *                                      When using the @ref nrf_fstorage_sd, this error
 *                                      indicates that the internal queue of operations is full.
 */

That part is not the description for nrf_fstorage_write(). It is the description for the function below (nrf_fstorage_erase()).

The description of nrf_fstorage_write() is above the line:

ret_code_t nrf_fstorage_write(nrf_fstorage_t const * p_fs,
                              uint32_t               dest,
                              void           const * p_src,
                              uint32_t               len,
                              void                 * p_param);

[Muqarrab]

Oh sorry, my bad.
Any suggestions for the issue?

[Muqarrab]

Hi Edvin
It's STRANGE. I have changed the initializing value and its work.

char      SNV_Data[]   ="Muqarrab112";
char Test_SNV_Data[]   ="Muqarrab112";

[Edvin]

did you find the reason? I am trying to make you understand what the return value means. Did you check the description above nrf_fstorage_write() in the .h file?

It works now, but you may encounter it later, and come back to us, either with the same issue, or a similar one. I am trying to explain how to debug these kind of return values. 

So let me help you. The description of nrf_fstorage_write() says:

/**@brief   Function for writing data to flash.
 *
 * Write @p len bytes from @p p_src to @p dest.
 *
 * When using @ref nrf_fstorage_sd, the data is written by several calls to @ref sd_flash_write if
 * the length of the data exceeds @ref NRF_FSTORAGE_SD_MAX_WRITE_SIZE bytes.
 * Only one event is sent upon completion.
 *
 * @note The data to be written to flash must be kept in memory until the operation has
 *       terminated and an event is received.
 *
 * @param[in]   p_fs        The fstorage instance.
 * @param[in]   dest        Address in flash memory where to write the data.
 * @param[in]   p_src       Data to be written.
 * @param[in]   len         Length of the data (in bytes).
 * @param[in]   p_param     User-defined parameter passed to the event handler (may be NULL).
 *
 * @retval  NRF_SUCCESS                 If the operation was accepted.
 * @retval  NRF_ERROR_NULL              If @p p_fs or @p p_src is NULL.
 * @retval  NRF_ERROR_INVALID_STATE     If the module is not initialized.
 * @retval  NRF_ERROR_INVALID_LENGTH    If @p len is zero or not a multiple of the program unit,
 *                                      or if it is otherwise invalid.
 * @retval  NRF_ERROR_INVALID_ADDR      If the address @p dest is outside the flash memory
 *                                      boundaries specified in @p p_fs, or if it is unaligned.
 * @retval  NRF_ERROR_NO_MEM            If no memory is available to accept the operation.
 *                                      When using the @ref nrf_fstorage_sd, this error
 *                                      indicates that the internal queue of operations is full.
 */
ret_code_t nrf_fstorage_write(nrf_fstorage_t const * p_fs,
                              uint32_t               dest,
                              void           const * p_src,
                              uint32_t               len,
                              void                 * p_param);

What does it say about NRF_ERROR_INVALID_LENGTH? It explains two scenarios, and a hint is that the issue was not that the length was 0, because len was 5. So it is related to the length, right?

[Muqarrab]

Hi Edvin.

I think flash memory is very sensitive. 
Now I am adding the Flash memory part to my main project.
So here are some new points I want to discuss.

1-I have made these functions to read/write. As per your instruction.

char      SNV_Data[]   ="Muqarrab112";
char Test_SNV_Data[]   ="11223344556";


/////////////////////////////////////////////////////////////////////////////// SNV

void write_SNV()
{
    ret_code_t rc;
    //SNV_Data[0]=0xEE;



    sd_flash_page_erase(0xf4);

    NRF_LOG_INFO("Writing \"%s\" to flash.", SNV_Data);
    rc = nrf_fstorage_write(&fstorage, 0xf4000, SNV_Data, sizeof(SNV_Data), NULL);
    APP_ERROR_CHECK(rc);

    wait_for_flash_ready(&fstorage);
    NRF_LOG_INFO("Writing Done");

}

uint32_t read_SNV()
{
    ret_code_t rc;

    rc = nrf_fstorage_read(&fstorage, 0xf4000, Test_SNV_Data, sizeof(Test_SNV_Data));
    APP_ERROR_CHECK(rc);


    NRF_LOG_INFO("Reading from flash hex:");
    for(uint8_t i=0; i<sizeof(Test_SNV_Data); i++)
    {
        NRF_LOG_RAW_INFO("%02x:", Test_SNV_Data[i]);
    //    NRF_LOG_INFO("Reading from flash char Hex %h :",Test_SNV_Data[i] );
    }

    NRF_LOG_RAW_INFO("\r\n");
    NRF_LOG_INFO("Reading from flash char:");
    for(uint8_t i=0; i<sizeof(Test_SNV_Data); i++)
    {
        NRF_LOG_RAW_INFO("%c", Test_SNV_Data[i]);
    }
    NRF_LOG_RAW_INFO("\r\n");

    NRF_LOG_INFO("Reading Done");
}
/////////////////////////////////////////////////////////////////////////////// SNV

Why I am getting this warning?

2-I am calling these two functions in main and they are working fine.

BUT when I am calling after connection they are not responding anything? NO RESPONSE from this function(When I write on characteristic 9 I call this function) even not print anything.
As I comment  write_SNV(); read_SNV(); these functions print statment start wotking.
What is the problem? Does any suggestion please?

void Charcteristics_9(uint8_t test)
{
    NRF_LOG_INFO("Memory Function");

    SNV_Data[0]=0xEE;
    write_SNV();
    read_SNV();
    ble_cus_custom_value_update(p_cus,5,9);

}

3-

Edvin said:

The secure_bootloader\pca10056_s140_ble bootloader has a flash start address of 0xf8000. So if you use this one, then it means that the FDS pages are on 0xF7000, 0xF6000 and 0xF5000. You can use 0xF4000->0xF4FFF. 

I have set the following address to store values.

NRF_FSTORAGE_DEF(nrf_fstorage_t fstorage) =
{
    /* Set a handler for fstorage events. */
    .evt_handler = fstorage_evt_handler,

    /* These below are the boundaries of the flash space assigned to this instance of fstorage.
     * You must set these manually, even at runtime, before nrf_fstorage_init() is called.
     * The function nrf5_flash_end_addr_get() can be used to retrieve the last address on the
     * last page of flash available to write data. */
    .start_addr = 0xf4000,
    .end_addr   = 0xf4fff,
};

Any suggestion,s please?