ReRAM 2 Click Board™

Product Code: MIKROE-4895

How Does The ReRAM 2 Click Board™ Work? The ReRAM 2 Click Board™ as its foundation uses the MB85AS8MT, a highly reliable 8Mbit resistive random-access memory (ReRAM) organized as 1,048,576 words of 8 bits from Fujitsu Semiconductor. It uses the resistance-variable memory process and silicon-gate CMOS process technologies to form nonvolatile memory cells. The MB85AS8MT specifies 1.000.000 endurance cycles with data retention of a minimum of 10 years, which gives the MB85AS8MT the capability to handle unlimited reads/writes to the memory. One prominent feature of the MB85AS8MT is an extremely small average current, despite its large density, for reading operations of 0.15mA at an operating frequency of 5MHz, which is only 5% of large density EEPROM devices. This feature enables minimal power consumption when in applications with frequent data-read operations. Besides higher write endurance, it has faster write speeds than EEPROM and flash memory, while its electric specifications, such as commands and timings, are compatible with EEPROM products.

The ReRAM 2 Click Board™ communicates with MCU through a standard SPI interface that enables high clock speeds up to 10MHz, supporting the two most common SPI modes, SPI Mode 0 and 3. An additional feature of this Click board™ represents the configurable Write Protection function labeled as WP routed on the PWM pin of the mikroBUS™ socket. The WP pin protects the entire memory and all registers from write operations and must be set to a low logic state to inhibit all the write operations. All memory and register writes are prohibited when this pin is low, and the address counter is not incremented. Besides, the ReRAM 2 Click Board™ also has an additional HOLD pin, routed to the RST pin of the mikroBUS™ socket labeled as HO, to interrupt a serial operation without aborting it. The ReRAM 2 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. However, the Click board™ comes equipped with a library containing functions and an example code that can be used, as a reference, for further development. SPECIFICATIONS Type ReRAM Applications Can be used as a nonvolatile storage media or temporary RAM expansion for storing variables in any embedded application that requires rapid writes and unlimited endurance On-board modules MB85AS8MT - highly reliable resistive random-access memory (ReRAM) from Fujitsu Semiconductor Key Features 8 Mbits (1,048,576 words x 8 bits), 256 bytes buffer size, high endurance and data retention, fast serial interface, sophisticated write protection scheme, and more Interface SPI Compatibility mikroBUS Click board size S (28.6 x 25.4 mm) Input Voltage 3.3V PINOUT DIAGRAM This table shows how the pinout of the ReRAM 2 Click Board™ corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns). Notes Pin Pin Notes NC 1 AN PWM 16 WP Write Protection SPI Suspension HO 2 RST INT 15 NC SPI Chip Select CS 3 CS RX 14 NC SPI Clock SCK 4 SCK TX 13 NC SPI Data OUT SDO 5 MISO SCL 12 NC SPI Data IN SDI 6 MOSI SDA 11 NC Power Supply 3.3V 7 3.3V 5V 10 NC Ground GND 8 GND GND 9 GND Ground ONBOARD SETTINGS AND INDICATORS Label Name Default Description LD1 PWR - Power LED Indicator RERAM 2 CLICK ELECTRICAL SPECIFICATIONS Description Min Typ Max Unit Supply Voltage - 3.3 -