ReRAM 2 Click

ReRAM 2 Click is a compact add-on board containing highly reliable resistive random-access memory. This board features the MB85AS8MT, an 8Mbit memory organized as 1,048,576 words of 8 bits from Fujitsu Semiconductor. The MB85AS8MT uses the resistance-variable memory process and silicon-gate CMOS process technologies to form nonvolatile memory cells. This SPI configurable ReRAM can withstand many write cycles (1x106 rewrite operations), has a data retention period greater than ten years, and can read and write to random addresses with very negligible delay. This Click board™ is ideal as a nonvolatile storage media or temporary RAM expansion for storing variables in any embedded application that requires rapid writes and unlimited endurance.

Click Product page

Click library

• Author : Nenad Filipovic
• Date : Nov 2021.
• Type : SPI type

Software Support

We provide a library for the ReRAM 2 Click as well as a demo application (example), developed using MikroElektronika compilers. The demo can run on all the main MikroElektronika development boards.

Package can be downloaded/installed directly from NECTO Studio Package Manager(recommended way), downloaded from our LibStock™ or found on Mikroe github account.

Library Description

This library contains API for ReRAM 2 Click driver.

Standard key functions :

• reram2_cfg_setup Config Object Initialization function.

  void reram2_cfg_setup ( reram2_cfg_t *cfg );

• reram2_init Initialization function.

  err_t reram2_init ( reram2_t *ctx, reram2_cfg_t *cfg );

• reram2_default_cfg Click Default Configuration function.

  err_t reram2_default_cfg ( reram2_t *ctx );

Example key functions :

• reram2_read_device_id ReRAM 2 read device ID function.

  err_t reram2_read_device_id ( reram2_t *ctx, reram2_dev_id_t *dev_id );

• reram2_write_memory ReRAM 2 write memory function.

  err_t reram2_write_memory ( reram2_t *ctx, uint32_t mem_addr, uint8_t *data_in, uint16_t len );

• reram2_read_memory ReRAM 2 read memory function.

  err_t reram2_read_memory ( reram2_t *ctx, uint32_t mem_addr, uint8_t *data_out, uint16_t len );

Example Description

This library contains API for ReRAM 2 Click driver.

The demo application is composed of two sections :

Application Init

Initializes SPI driver and log UART. After driver initialization the app set default settings, performs device wake-up, check Device ID, set Write Enable Latch command and write demo_data string ( mikroE ), starting from the selected memory_addr ( 1234 ).

void application_init ( void )
{
    log_cfg_t log_cfg;        /**< Logger config object. */
    reram2_cfg_t reram2_cfg;  /**< Click 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.
    reram2_cfg_setup( &reram2_cfg );
    RERAM2_MAP_MIKROBUS( reram2_cfg, MIKROBUS_1 );
    if ( SPI_MASTER_ERROR == reram2_init( &reram2, &reram2_cfg ) )
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }

    if ( RERAM2_ERROR == reram2_default_cfg ( &reram2 ) )
    {
        log_error( &logger, " Default configuration." );
        for ( ; ; );
    }

    reram2_wake_up( &reram2 );
    Delay_ms ( 100 );

    if ( RERAM2_ERROR == reram2_check_device_id( &reram2 ) )
    {
        log_error( &logger, " Communication Error. " );
        log_info( &logger, " Please, run program again... " );
        for( ; ; );
    }

    reram2_send_command( &reram2, RERAM2_CMD_WREN );
    Delay_ms ( 100 );

    log_info( &logger, " Application Task " );

    memory_addr = 1234;   
    log_printf( &logger, "\r\n  Write data : %s", demo_data );
    reram2_write_memory( &reram2, memory_addr, &demo_data[ 0 ], 9 );
    log_printf( &logger, "-----------------------\r\n" );
    Delay_ms ( 1000 );
}

Application Task

This is an example that demonstrates the use of the ReRAM 2 Click board™. In this example, we read and display a data string, which we have previously written to memory, starting from the selected memory_addr ( 1234 ). Results are being sent to the Usart Terminal where you can track their changes.

void application_task ( void )
{
    static char rx_data[ 9 ] = { 0 };

    reram2_read_memory( &reram2, memory_addr, &rx_data[ 0 ], 9 );
    log_printf( &logger, "  Read data  : %s", rx_data ); 
    log_printf( &logger, "-----------------------\r\n" );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
}

The full application code, and ready to use projects can be installed directly from NECTO Studio Package Manager(recommended way), downloaded from our LibStock™ or found on Mikroe github account.

Other Mikroe Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.ReRAM2

Additional notes and informations

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. UART terminal is available in all MikroElektronika compilers.