Intermediate
30 min

Make safe data storage with CAV24C512 and STM32F091RC

Efficient nonvolatile data storage

EEPROM 8 Click with Nucleo-64 with STM32F091RC MCU

Published Feb 26, 2024

Click board™

EEPROM 8 Click

Dev Board

Nucleo-64 with STM32F091RC MCU

Compiler

NECTO Studio

MCU

STM32F091RC

Keep your data safe and secure in silicon for a century

A

A

Hardware Overview

How does it work?

EEPROM 8 Click is based on the CAV24C512, a 512-Kb EEPROM with an I2C interface and Write Protection Mode from ON Semiconductor. The CAV24C512 is organized as 65,536 words of 8 bits each and benefits from a wide power supply range and 100 years of data retention combining their unprecedented data storage with excellent energy efficiency. It is highly reliable, lasting one million full-memory read/write/erase cycles. On-chip Error Correction Code (ECC) makes this Click board™ suitable for high-reliability applications where dependable nonvolatile memory storage is essential.

This Click board™ communicates with MCU using the standard I2C 2-Wire interface that supports Standard (100 kHz), Fast (400 kHz), and Fast-Plus (1MHz) modes of operation. The CAV24C512 has a 7-bit slave address with the first five MSBs fixed to 1010. The address pins A0, A1, and A2 are programmed by the user and determine the value of the last three LSBs of the slave address, which can be selected by positioning onboard SMD jumpers labeled as ADDR SEL to an appropriate position marked as 0 or 1. Also, the configurable Write Protection function, the WP pin of the mikroBUS™

socket, allows the user to freeze the entire memory area, thus protecting it from Write instructions. This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the VCC SEL jumper. This way, both 3.3V and 5V capable MCUs can use the communication lines properly. However, the Click board™ comes equipped with a library containing easy-to-use functions and an example code that can be used, as a reference, for further development.

EEPROM 8 Click top side image
EEPROM 8 Click lateral side image
EEPROM 8 Click bottom side image

Features overview

Development board

Nucleo-64 with STM32F091RC MCU offers a cost-effective and adaptable platform for developers to explore new ideas and prototype their designs. This board harnesses the versatility of the STM32 microcontroller, enabling users to select the optimal balance of performance and power consumption for their projects. It accommodates the STM32 microcontroller in the LQFP64 package and includes essential components such as a user LED, which doubles as an ARDUINO® signal, alongside user and reset push-buttons, and a 32.768kHz crystal oscillator for precise timing operations. Designed with expansion and flexibility in mind, the Nucleo-64 board features an ARDUINO® Uno V3 expansion connector and ST morpho extension pin

headers, granting complete access to the STM32's I/Os for comprehensive project integration. Power supply options are adaptable, supporting ST-LINK USB VBUS or external power sources, ensuring adaptability in various development environments. The board also has an on-board ST-LINK debugger/programmer with USB re-enumeration capability, simplifying the programming and debugging process. Moreover, the board is designed to simplify advanced development with its external SMPS for efficient Vcore logic supply, support for USB Device full speed or USB SNK/UFP full speed, and built-in cryptographic features, enhancing both the power efficiency and security of projects. Additional connectivity is

provided through dedicated connectors for external SMPS experimentation, a USB connector for the ST-LINK, and a MIPI® debug connector, expanding the possibilities for hardware interfacing and experimentation. Developers will find extensive support through comprehensive free software libraries and examples, courtesy of the STM32Cube MCU Package. This, combined with compatibility with a wide array of Integrated Development Environments (IDEs), including IAR Embedded Workbench®, MDK-ARM, and STM32CubeIDE, ensures a smooth and efficient development experience, allowing users to fully leverage the capabilities of the Nucleo-64 board in their projects.

Nucleo 64 with STM32F091RC MCU double side image

Microcontroller Overview

MCU Card / MCU

default

Architecture

ARM Cortex-M0

MCU Memory (KB)

256

Silicon Vendor

STMicroelectronics

Pin count

64

RAM (Bytes)

32768

You complete me!

Accessories

Click Shield for Nucleo-64 comes equipped with two proprietary mikroBUS™ sockets, allowing all the Click board™ devices to be interfaced with the STM32 Nucleo-64 board with no effort. This way, Mikroe allows its users to add any functionality from our ever-growing range of Click boards™, such as WiFi, GSM, GPS, Bluetooth, ZigBee, environmental sensors, LEDs, speech recognition, motor control, movement sensors, and many more. More than 1537 Click boards™, which can be stacked and integrated, are at your disposal. The STM32 Nucleo-64 boards are based on the microcontrollers in 64-pin packages, a 32-bit MCU with an ARM Cortex M4 processor operating at 84MHz, 512Kb Flash, and 96KB SRAM, divided into two regions where the top section represents the ST-Link/V2 debugger and programmer while the bottom section of the board is an actual development board. These boards are controlled and powered conveniently through a USB connection to program and efficiently debug the Nucleo-64 board out of the box, with an additional USB cable connected to the USB mini port on the board. Most of the STM32 microcontroller pins are brought to the IO pins on the left and right edge of the board, which are then connected to two existing mikroBUS™ sockets. This Click Shield also has several switches that perform functions such as selecting the logic levels of analog signals on mikroBUS™ sockets and selecting logic voltage levels of the mikroBUS™ sockets themselves. Besides, the user is offered the possibility of using any Click board™ with the help of existing bidirectional level-shifting voltage translators, regardless of whether the Click board™ operates at a 3.3V or 5V logic voltage level. Once you connect the STM32 Nucleo-64 board with our Click Shield for Nucleo-64, you can access hundreds of Click boards™, working with 3.3V or 5V logic voltage levels.

Click Shield for Nucleo-64 accessories 1 image

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
NC
NC
RST
NC
NC
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
Write Protect
PC8
PWM
NC
NC
INT
NC
NC
TX
NC
NC
RX
I2C Clock
PB8
SCL
I2C Data
PB9
SDA
Power Supply
5V
5V
Ground
GND
GND
1

Take a closer look

Schematic

EEPROM 8 Click Schematic schematic

Step by step

Project assembly

Click Shield for Nucleo-64 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Nucleo-64 with STM32F091RC MCU as your development board.

Click Shield for Nucleo-64 front image hardware assembly
Nucleo 64 with STM32F401RE MCU front image hardware assembly
EEPROM 13 Click front image hardware assembly
Prog-cut hardware assembly
Nucleo-64 with STM32XXX MCU MB 1 Mini B Conn - upright/background hardware assembly
Necto image step 2 hardware assembly
Necto image step 3 hardware assembly
Necto image step 4 hardware assembly
Necto image step 5 hardware assembly
Necto image step 6 hardware assembly
Clicker 4 for STM32F4 HA MCU Step hardware assembly
Necto No Display image step 8 hardware assembly
Necto image step 9 hardware assembly
Necto image step 10 hardware assembly
Debug Image Necto Step hardware assembly

Track your results in real time

Application Output via Debug Mode

1. Once the code example is loaded, pressing the "DEBUG" button initiates the build process, programs it on the created setup, and enters Debug mode.

2. After the programming is completed, a header with buttons for various actions within the IDE becomes visible. Clicking the green "PLAY" button starts reading the results achieved with the Click board™. The achieved results are displayed in the Application Output tab.

DEBUG_Application_Output

Software Support

Library Description

This library contains API for EEPROM 8 Click driver.

Key functions:

  • eeprom8_write_page This function writes up to 128 bytes of data starting from the selected register.

  • eeprom8_read_random_byte This function reads one byte data from the desired register.

  • eeprom8_read_sequential This function reads the desired number of bytes starting from the selected register.

Open Source

Code example

This example can be found in NECTO Studio. Feel free to download the code, or you can copy the code below.

/*!
 * @file main.c
 * @brief EEPROM8 Click example
 *
 * # Description
 * This example demonstrates the use of EEPROM 8 click board by writing specified data to
 * the memory and reading it back.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initializes the driver and USB UART logging.
 *
 * ## Application Task
 * Task writes a desired number of data bytes to the EEPROM 8 memory 
 * and verifies that it is written correctly by reading from the same memory location and 
 * in case of successful read, displays the memory content on the USB UART. 
 * This is done in two passes.
 *
 * @author Stefan Popovic
 *
 */

#include "board.h"
#include "log.h"
#include "eeprom8.h"

static eeprom8_t eeprom8;
static log_t logger;

// Number of test bytes
#define TEST_NBYTES ( 150 )

// Starting address for example
#define TEST_MEM_LOCATION ( EEPROM8_BLOCK_ADDR_START + 1024ul )

static uint8_t  cnt = 0;
static uint8_t  test_write_buffer[ TEST_NBYTES ]  = { 0 };
static uint8_t  test_read_buffer[ TEST_NBYTES ]   = { 0 };
static uint16_t addr_offset = TEST_MEM_LOCATION;

/**
 * @brief First pass function
 * @details This function writes and reads defined number of bytes
 *  with zero values
 * @param[in] ctx  Click object.
 * @param[in] write_buf  Data to be written.
 * @param[out] read_buf  Data to be read.
 * @return @li @c  0 - Success,
 *         @li @c -1 - Error.
 * See #err_t definition for detailed explanation.
 * @note None.
 */
err_t run_first_pass( eeprom8_t* ctx, uint8_t* write_buf, uint8_t* read_buf );

/**
 * @brief Second pass function
 * @details This function writes and reads defined number of bytes
 *  with the values following arithmetical progression
 * @param[in] ctx  Click object.
 * @param[in] write_buf  Data to be written.
 * @param[out] read_buf  Data to be read.
 * @return @li @c  0 - Success,
 *         @li @c -1 - Error.
 * See #err_t definition for detailed explanation.
 * @note None.
 */
err_t run_second_pass( eeprom8_t* ctx, uint8_t* write_buf, uint8_t* read_buf );

void application_init ( void ) 
{
    eeprom8_cfg_t eeprom8_cfg;  /**< Click config object. */
    log_cfg_t log_cfg;          /**< Logger config object. */
    
    /** 
     * Logger initialization.
     * Default baud rate: 115200
     * Default log level: LOG_LEVEL_DEBUG
     * @note If USB_UART_RX and USB_UART_TX 
     * are defined as HAL_PIN_NC, you will 
     * need to define them manually for log to work. 
     * See @b LOG_MAP_USB_UART macro definition for detailed explanation.
     */
    LOG_MAP_USB_UART( log_cfg );
    log_init( &logger, &log_cfg );
    log_info( &logger, " Application Init " );
    
    //  Click initialization.
    eeprom8_cfg_setup( &eeprom8_cfg );
    EEPROM8_MAP_MIKROBUS( eeprom8_cfg, MIKROBUS_1 );
    if ( I2C_MASTER_ERROR == eeprom8_init( &eeprom8, &eeprom8_cfg ) )
    {
        log_error( &logger, " Communication Init " );
        for ( ; ; );
    }
    
    log_info( &logger, " Application Task " );
}

void application_task ( void ) 
{
    // Reset variables
    cnt = 0;
    memset( test_read_buffer, 0, sizeof ( test_read_buffer ) );
    addr_offset = TEST_MEM_LOCATION;
    
    // Initiate first pass 
    //  filling the eeprom addresses with zeros 
    if( EEPROM8_ERROR == run_first_pass( &eeprom8, test_write_buffer, test_read_buffer ) )
    {
        log_error( &logger, " First Pass Failed " );
    }
    
    // Initiate second pass 
    //  filling the eeprom addresses with values following arithmetic sequence with difference of 1 
    if( EEPROM8_ERROR == run_second_pass( &eeprom8, test_write_buffer, test_read_buffer ) )
    {
        log_error( &logger, " Second Pass Failed " );
    }
    
    log_printf( &logger, " \r\nInitiating new iteration\r\n " );
    Delay_ms( 6000 );
}

void main ( void ) 
{
    application_init( );

    for ( ; ; ) 
    {
        application_task( );
    }
}

// First pass: writing zero values into eeprom memory and reading them back
err_t run_first_pass( eeprom8_t* ctx, uint8_t* write_buf, uint8_t* read_buf )
{
    // Fill write buffer with zeros
    memset( write_buf, 0, TEST_NBYTES );
    
    // Fill whole page with zeros using page write operation
    eeprom8_write_enable( ctx );
    if ( EEPROM8_ERROR == eeprom8_write_page( ctx, addr_offset, write_buf ) )
    {
        log_error( &logger, " Write Page Failed " );
        return EEPROM8_ERROR;
    }
    cnt += EEPROM8_NBYTES_PAGE;
    
    // Fill remaining adresses with zero using byte write operation
    addr_offset += EEPROM8_NBYTES_PAGE;

    while( cnt < TEST_NBYTES )
    {
        if ( EEPROM8_ERROR == eeprom8_write_byte( ctx, addr_offset++, 0 ) )
        {
            log_error( &logger, " Write %d. Byte Failed ", ( uint16_t ) cnt );
            return EEPROM8_ERROR;
        }
        cnt++;
        Delay_10ms( );
    }
    eeprom8_write_protect( ctx );

    Delay_1sec( );
    
    // Read defined number of bytes starting from the test memory location
    addr_offset = TEST_MEM_LOCATION;
    if ( EEPROM8_ERROR == eeprom8_read_sequential( ctx, addr_offset, TEST_NBYTES, read_buf ) )
    {
         log_error( &logger, "Read Sequential Failed" );
         return EEPROM8_ERROR;
    }
  
    // compare written and read buffers and log data in case of a match 
    if ( memcmp( write_buf, read_buf, sizeof( write_buf ) ) == 0 )
    {
        log_printf( &logger, 
                    " \r\nFirst pass: reading %d bytes data starting from eeprom address 0x%x\r\n ", 
                    ( uint16_t ) TEST_NBYTES, 
                    ( uint32_t ) TEST_MEM_LOCATION );
        for ( cnt = 0; cnt < TEST_NBYTES; cnt++ )
        {
            log_printf( &logger, " %d", ( uint16_t ) read_buf[ cnt ] );
            Delay_ms( 50 );
        }
    
        log_printf( &logger, "\r\n\r\n" );
    }
    else
    {
        return EEPROM8_ERROR;
    }
    return EEPROM8_OK;
}

// Second pass: writing incremental values into eeprom memory and reading them back
err_t run_second_pass( eeprom8_t* ctx, uint8_t* write_buf, uint8_t* read_buf )
{
    for ( cnt = 0; cnt < TEST_NBYTES; cnt++ )
    {
        write_buf[ cnt ] = cnt + 1;
    }
    // Write buffer data using page write operation
    cnt = 0;
    eeprom8_write_enable( ctx );
    if ( EEPROM8_ERROR == eeprom8_write_page( ctx, addr_offset, write_buf ) )
    {
        log_error( &logger, " Write Page Failed ");
        return EEPROM8_ERROR;
    }
    cnt += EEPROM8_NBYTES_PAGE;
    
    // Write remaining buffer data using byte write operation
    addr_offset += EEPROM8_NBYTES_PAGE;

    while ( cnt < TEST_NBYTES )
    {
        if ( EEPROM8_ERROR == eeprom8_write_byte( ctx, addr_offset++, write_buf[ cnt++ ] ) )
        {
            log_error( &logger, " Write %d. Byte Failed ", ( uint16_t ) cnt );
            return EEPROM8_ERROR;
        }
        Delay_10ms( );
    }
    eeprom8_write_protect( ctx );

    Delay_ms( 1000 );
    
    // Read bytes of the page size starting from the test memory location
    addr_offset = TEST_MEM_LOCATION;
    if ( EEPROM8_ERROR == eeprom8_read_sequential( ctx, addr_offset, EEPROM8_NBYTES_PAGE, read_buf ) )
    {
        log_error( &logger, " Read Sequential Failed " );
        return EEPROM8_ERROR;
    }
    
    // Read two bytes with random byte read operation
    addr_offset += EEPROM8_NBYTES_PAGE;
    cnt = EEPROM8_NBYTES_PAGE;

    if( EEPROM8_ERROR == eeprom8_read_random_byte( ctx, addr_offset, &read_buf[ cnt++ ] ) )
    {
        log_error( &logger, " Read %d. Random Byte Failed ", ( uint16_t ) cnt-1 );
        return EEPROM8_ERROR;
    }
    ++addr_offset;
    if( EEPROM8_ERROR == eeprom8_read_random_byte( ctx, addr_offset, &read_buf[ cnt++ ] ) )
    {
        log_error( &logger, " Read %d. Random Byte Failed ", ( uint16_t ) cnt-1 );
        return EEPROM8_ERROR;
    }
    
    // Read the rest of the bytes with current address read operation
    while ( cnt < TEST_NBYTES )
    {
        if( EEPROM8_ERROR == eeprom8_read_current_byte( ctx, &read_buf[ cnt++ ] ) )
        {
            log_error( &logger, " Read %d. Current Byte Failed ", ( uint16_t ) cnt-1 );
            return EEPROM8_ERROR;
        }
    }
    // compare written and read buffers and log data in case of a match
    if ( memcmp( write_buf, read_buf, TEST_NBYTES ) == 0 )
    {
        log_printf( &logger, 
                    " \r\nSecond pass: reading %d bytes data starting from eeprom address 0x%x\r\n ", 
                    ( uint16_t ) TEST_NBYTES, 
                    ( uint32_t ) TEST_MEM_LOCATION );
        for ( cnt = 0; cnt < TEST_NBYTES; cnt++ )
        {
            log_printf( &logger, " %d", ( uint16_t )read_buf[ cnt ] );
            Delay_ms( 50 );
        }
    
        log_printf( &logger, "\r\n\r\n" );
    }
    else
    {
        return EEPROM8_ERROR;
    }
    return EEPROM8_OK;
}

// ------------------------------------------------------------------------ END

Additional Support

Resources

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