Library Description

Initializes and defines SPI bus driver, driver functions which communicate with the memory array and configures click to the writable state.

Key functions

uint8_t eeprom4_sendCommand(uint8_t command_byte);- The function sends command (instruction) to the click. In case that command byte is _EEPROM4_LOW_POWER_WRITE_POLL_COMMAND (0x08) function returns 0x00 if a part is not in a write cycle and returns 0xFF if the part is still busy completing the write cycle. In other cases, the function returns 0.

void eeprom4_writeStatusReg(uint8_t data_value);- The function writes data determined in the parameter of the function to the status register.

uint8_t eeprom4_readStatusReg(void);- The function reads a one-byte data value from the status register.

void eeprom4_writeMemory(uint32_t memory_address, uint8_t *data_input, uint8_t nBytes);- The function writes a number of bytes determined by nBytes parameter from buffer determined by data_input pointer to memory location determined by memory_address parameter.

void eeprom4_readMemory(uint32_t memory_address, uint8_t *data_output, uint8_t nBytes);- The function reads a number of bytes determined by nBytes parameter from memory location determined by memory_address parameter and stores bytes to buffer determined by data_output pointer.

void eeprom4_enableWriteProtect(uint8_t state);- The function sets RST pin on state value to enable or disable writing to status register and memory array. WP pin is used in conjunction with the block protection bits of the status register and with WPEN and WEL bits also.

void eeprom4_enableHoldOperation(uint8_t state);- The function enables or disables the Hold operation. To pause the serial communication with the master device without resetting the serial sequence, the HOLD pin must be brought low. To resume serial communication, HOLD pin must be brought high.

uint8_t eeprom4_checkStatusReg(uint8_t check_bit);- The function checks the value of the status register bit determined by check_bit parameter.

Examples Description

The application is composed of three sections :

• System Initialization - Initializes peripherals and pins.
• Application Initialization - Initializes click driver and configures click that all memory block is unprotected. Also configures that HOLD operation is disabled, and the memory and status register are writable.
• Application Task - (code snippet) - Enables writing to the memory array, writes data from the buffer to the memory, checks if the part is in a write cycle, and if is not reads data from memory array and stores data to buffer. Shows data on USB UART.

void applicationTask()
{
    eeprom4_sendCommand(_EEPROM4_SET_WRITE_ENABLE_LATCH_COMMAND);

    eeprom4_writeMemory(_EEPROM4_FIRST_MEMORY_LOCATION, &data_write[0], 8);

    cnt = eeprom4_checkStatusReg(_EEPROM4_READY_BIT);

    check_state = eeprom4_sendCommand(_EEPROM4_LOW_POWER_WRITE_POLL_COMMAND);

    while(cnt | check_state)
    {
        cnt = eeprom4_checkStatusReg(_EEPROM4_READY_BIT);

        check_state = eeprom4_sendCommand(_EEPROM4_LOW_POWER_WRITE_POLL_COMMAND);
    }

    eeprom4_readMemory(0x00000001, &data_read[0], 6);

    for(cnt = 0; cnt < 6; cnt++)
    {
        WordToStr(data_read[cnt], text);
        mikrobus_logWrite(text, _LOG_TEXT);
        if(cnt < 5)
        {
            mikrobus_logWrite(",", _LOG_TEXT);
        }else
        {
            mikrobus_logWrite("", _LOG_LINE);
        }
    }

    Delay_ms(2000);
}

MikroElektronika Libraries used in the example:

• Conversions
• SPI
• UART

Additional notes and information

Depending on the development board you are using, you may need USB UART click,  USB UART 2 click or  RS232 click to connect to your PC, for development systems with no UART to USB interface available on the board. The terminal available in all MikroElektronika compilers, or any other terminal application of your choice, can be used to read the message.