Nrthugu

Using the ATting1616 within avr-gcc I am trying to read and write to the EEPROM.

The ATtiny1616 uses NVMCTRL - Nonvolatile Memory Controller for byte level read/writes. I am using NVMCTRL to read/write blocks from the EEPROM, but it is not working correctly.

Here is an example to demonstrate what I am trying to so.

Lets say that I was to save two different values within the EEPROM and then read back each ones value.

uint16_t eeprom_address1 = 0x01;//!< Address one for first saved value

uint16_t eeprom_address2 = 0x32;//!< Address two for second saved value



char save_one = "12345"; //!< Test value to save, one

char save_two = "testing";//!< Test value to save, two





FLASH_0_write_eeprom_block(eeprom_address1,save_one,7); //!< Save first value to address 1

FLASH_0_write_eeprom_block(eeprom_address2,save_two,7); //!< Save second value to address 2





char test_data[7] = {0}; //!< Just some empty array to put chars into



FLASH_0_read_eeprom_block(eeprom_address1,test_data,7); //!< Read eeprom from address, to address+ 7, and store back into test_data

Here are the read/write functions:

#  define EEPROM_START     (0x1400)//!< is located in header file

/**

 * brief Read a block from eeprom

 *

 * param[in] eeprom_adr The byte-address in eeprom to read from

 * param[in] data Buffer to place read data into

 *

 * return Nothing

 */

void FLASH_0_read_eeprom_block(eeprom_adr_t eeprom_adr, uint8_t *data, size_t size)

{



    // Read operation will be stalled by hardware if any write is in progress



    memcpy(data, (uint8_t *)(EEPROM_START + eeprom_adr), size);

}



/**

 * brief Write a block to eeprom

 *

 * param[in] eeprom_adr The byte-address in eeprom to write to

 * param[in] data The buffer to write

 *

 * return Status of write operation

 */

nvmctrl_status_t FLASH_0_write_eeprom_block(eeprom_adr_t eeprom_adr, uint8_t *data, size_t size)

{



    uint8_t *write = (uint8_t *)(EEPROM_START + eeprom_adr);



    /* Wait for completion of previous write */

    while (NVMCTRL.STATUS & NVMCTRL_EEBUSY_bm)

        ;



    /* Clear page buffer */

    ccp_write_spm((void *)&NVMCTRL.CTRLA, NVMCTRL_CMD_PAGEBUFCLR_gc);



    do {

        /* Write byte to page buffer */

        *write++ = *data++;

        size--;

        // If we have filled an entire page or written last byte to a partially filled page

        if ((((uintptr_t)write % EEPROM_PAGE_SIZE) == 0) || (size == 0)) {

            /* Erase written part of page and program with desired value(s) */

            ccp_write_spm((void *)&NVMCTRL.CTRLA, NVMCTRL_CMD_PAGEERASEWRITE_gc);

        }

    } while (size != 0);



    return NVM_OK;

}

The value that is turned if test_data[7] is printed will be "testing".
When looking at the memory in debug mode I am able to see that the value is always being written to the first memory location in the data EEPROM.[0x1400]
In this case starting at memory 0x1400 the value of "testing" starts.

There seems to be something fundamental that I have failed to understand with reading and write to the EEPROM. Any guidance would be greatly appreciated.