Unlock the potential of data storage with MB85AS4MT and PIC18F57K42
ReRAM: Your gateway to speed, efficiency, and data density
Published Oct 18, 2023
Click board™
ReRAM Click
Dev Board
UNI-DS v8
Compiler
NECTO Studio
MCU
PIC18F57K42
Explore how ReRAM is reshaping the memory landscape, delivering faster, more efficient data storage solutions for the modern world
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Hardware Overview
How does it work?
ReRAM Click board is based on the MB85AS4MT, a 4Mb serial SPI ReRAM memory module from Fujitsu. This module contains 524.288 x 8 bits of memory that can be randomly accessed. The pinout of the used memory module is the same as most commonly used EEPROM modules so that it can directly replace it. The usual SPI lines - SO, SI, SCK and #CS pins from the MB85AS4MT IC are routed to the mikroBUS™ SPI port (MISO, MOSI, SCK and CS pins). Besides the SPI serial bus, there are two more pins routed to the mikroBUS™. The #HOLD pin of the MB85AS4MT IC is routed to the RST pin of the mikroBUS™ and it is used to hold the data transfer. When this pin is pulled to a LOW logic level, all data transfer operations are suspended. However, this function is enabled only when the device is already addressed with the CS
pin pulled to a LOW level. This allows to pause the data transfer and resume it later without the need to first address it via the CS pin, reducing the output latency that way. While the data transfer is paused, the SO pin will switch to a high impedance mode (HIGH Z) and will remain inactive. The SCK pulses are completely ignored. The #HOLD pin of the MB85AS4MT IC is pulled to a HIGH logic level by an onboard pull-up resistor. The #WP pin of the MB85AS4MT IC is routed to the PWM pin of the mikroBUS™ and it is used to prevent writes to the status register, acting as a hardware write protect pin. It is routed to the RST pin of the mikroBUS™. The logical organization of the module, such as read and write commands and the status register of the MB85AS4MT IC are the same as with most commonly used
EEPROM modules, such as the one used in EEPROM 4 click. That allows this memory module, as well as ReRAM click to replace the existing EEPROM module with not too much additional work. The provided libraries offer all the functions needed to work with the ReRAM click. Their usage is demonstrated in the included example application which can be used as a reference for further development. This Click board™ can be operated only with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. Also, it comes equipped with a library containing functions and an example code that can be used as a reference for further development.
Features overview
Development board
UNI-DS v8 is a development board specially designed for the needs of rapid development of embedded applications. It supports a wide range of microcontrollers, such as different STM32, Kinetis, TIVA, CEC, MSP, PIC, dsPIC, PIC32, and AVR MCUs regardless of their number of pins, and a broad set of unique functions, such as the first-ever embedded debugger/programmer over WiFi. The development board is well organized and designed so that the end-user has all the necessary elements, such as switches, buttons, indicators, connectors, and others, in one place. Thanks to innovative manufacturing technology, UNI-DS v8 provides a fluid and immersive working experience, allowing access anywhere and under any
circumstances at any time. Each part of the UNI-DS v8 development board contains the components necessary for the most efficient operation of the same board. An advanced integrated CODEGRIP programmer/debugger module offers many valuable programming/debugging options, including support for JTAG, SWD, and SWO Trace (Single Wire Output)), and seamless integration with the Mikroe software environment. Besides, it also includes a clean and regulated power supply module for the development board. It can use a wide range of external power sources, including a battery, an external 12V power supply, and a power source via the USB Type-C (USB-C) connector. Communication options such as USB-UART, USB
HOST/DEVICE, CAN (on the MCU card, if supported), and Ethernet is also included. In addition, it also has the well-established mikroBUS™ standard, a standardized socket for the MCU card (SiBRAIN standard), and two display options for the TFT board line of products and character-based LCD. UNI-DS v8 is an integral part of the Mikroe ecosystem for rapid development. Natively supported by Mikroe software tools, it covers many aspects of prototyping and development thanks to a considerable number of different Click boards™ (over a thousand boards), the number of which is growing every day.
Microcontroller Overview
MCU Card / MCU
Type
8th Generation
Architecture
PIC
MCU Memory (KB)
128
Silicon Vendor
Microchip
Pin count
48
RAM (Bytes)
8192
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Schematic
Step by step
Project assembly
Start by selecting your development board and Click board™. Begin with the UNI-DS v8 as your development board.
Track your results in real time
Application Output via UART Mode
1. Once the code example is loaded, pressing the "FLASH" button initiates the build process, and programs it on the created setup.
2. After the programming is completed, click on the Tools icon in the upper-right panel, and select the UART Terminal.
3. After opening the UART Terminal tab, first check the baud rate setting in the Options menu (default is 115200). If this parameter is correct, activate the terminal by clicking the "CONNECT" button.
4. Now terminal status changes from Disconnected to Connected in green, and the data is displayed in the Received data field.
Software Support
Library Description
This library contains API for ReRAM Click driver.
Key functions:
reram_send_cmd- Command Send functionreram_read_status- Status Read functionreram_write_memory- Memory Write function
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 ReRAM Click example
*
* # Description
* This example demonstrates the use of the ReRAM Click board.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initializes SPI serial interface and puts a device to the initial state.
* Data from 0 to 255 will be written in memory block from address 0x0 to
* address 0xFF.
*
* ## Application Task
* Reads same memory block starting from address 0x0 to address 0xFF and
* sends memory content to USB UART, to verify memory write operation.
*
* *note:*
* Write Enable Latch is reset after the following operations:
* - After 'Write Disable'command recognition.
* - The end of writing process after 'Write Status' command recognition.
* - The end of writing process after 'Write Memory' command recognition.
*
* Data will not be written in the protected blocks of the ReRAM array.
* - Upper 1/4 goes from address 0x60000 to 0x7FFFF.
* - Upper 1/2 goes from address 0x40000 to 0x7FFFF.
* - The entire ReRAM array goes from address 0x00000 to 0x7FFFF.
*
* \author Nemanja Medakovic
*
*/
// ------------------------------------------------------------------- INCLUDES
#include "board.h"
#include "log.h"
#include "reram.h"
// ------------------------------------------------------------------ VARIABLES
static reram_t reram;
static log_t logger;
static char write_buf[ ] = "MikroE";
static char read_buf[ 10 ] = { 0 };
// ------------------------------------------------------ APPLICATION FUNCTIONS
void application_init( void )
{
reram_cfg_t reram_cfg;
log_cfg_t logger_cfg;
// Click object initialization.
reram_cfg_setup( &reram_cfg );
RERAM_MAP_MIKROBUS( reram_cfg, MIKROBUS_1 );
reram_init( &reram, &reram_cfg );
// Click start configuration.
reram_default_cfg( &reram );
/**
* 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( logger_cfg );
log_init( &logger, &logger_cfg );
reram_wake_up( &reram );
uint32_t id_data = reram_read_id( &reram );
if ( RERAM_ID_DATA != id_data )
{
log_printf( &logger, "*** ReRAM Error ID ***\r\n" );
for( ; ; );
}
else
{
log_printf( &logger, "*** ReRAM Initialization Done ***\r\n" );
log_printf( &logger, "***********************************\r\n" );
}
reram_send_cmd( &reram, RERAM_CMD_WREN );
Delay_ms( 1000 );
}
void application_task( void )
{
log_printf( &logger, "* Writing data *\r\n" );
reram_write_memory( &reram, RERAM_MEM_ADDR_START, write_buf, 6 );
Delay_ms( 1000 );
reram_read_memory( &reram, RERAM_MEM_ADDR_START, read_buf, 6 );
log_printf( &logger, "* Read data:%s\r\n", read_buf );
Delay_ms( 2000 );
}
void main( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
// ------------------------------------------------------------------------ END
