====== LamaPLC: External FRAM memory module ======
**FRAM** (//Ferroelectric RAM or F-RAM//) memory modules combine the fast write speeds and near-infinite endurance of RAM with the data persistence of traditional non-volatile storage (like Flash or EEPROM).

**Key Advantages of FRAM Modules Over Flash/EEPROM**

  * **No Erase Cycle Required:** Unlike Flash memory, which forces you to erase an entire sector before writing, FRAM allows instant, bit-level or byte-level random writes.
  * **Astronomical Endurance:** Supports up to 10¹⁴ (100 trillion) write cycles, which is millions of times higher than standard EEPROM or Flash.
  * **Ultra-Low Power:** Consumes minimal energy during write operations because it doesn't require high-voltage charge pumps

==== MB85RC256 Non-Volatile FRAM Board with I²C communication ====
{{ :sensor:mb85rc256_1.png?180|MB85RC256 Non-Volatile FRAM Board with I²C communication}}
The MB85RC256 Non-Volatile FRAM Board is a high-performance memory breakout module built around Fujitsu's [[https://www.google.com/url?sa=i&source=web&rct=j&url=https://cdn-shop.adafruit.com/product-files/1895/MB85RC256V-DS501-00017-3v0-E.pdf&ved=2ahUKEwj17oCznPaVAxVnQ_EDHdVkC5sQy_kOegYIAAgKEAE&opi=89978449&cd&psig=AOvVaw0EZd63TKnWdRsmLKMXFXhm&ust=1785357309369000|MB85RC256V memory chip]]. It bridges the gap between RAM and EEPROM, offering non-volatile data persistence combined with instantaneous byte-level write speeds and extreme endurance.

=== MB85RC256 Technical Specifications ===
  * **Memory Capacity:** 256 Kilobits (Kb), which translates to exactly 32 Kbytes (KB).
  * **Memory Organization:** 32,768 words × 8 bits (byte-addressable from 0x0000 to 0x7FFF).
  * **Operating Voltage:** 2.7V to 5.5V (fully compatible with 3.3V and 5V microcontrollers like Arduino, STM32, and ESP32).
  * **Communication Interface:** Two-wire [[com:basic_i2c|I²C]] Fast Mode Plus.
  * **Max Clock Speed:** Up to 1.0 MHz.Read/Write Endurance: 1 Trillion (10¹²) to 10 Trillion (10¹³) cycles per byte.
  * **Data Retention:** 95 years at +55°C, or up to 200+ years at +35°C.
  * **Power Consumption:** 200 µA maximum active operating current (at 1 MHz), and ~27 µA standby current.

=== MB85RC256 Core Functional Mechanics ===

**No Write Delay (Instantaneous Commit)**

Traditional EEPROM or Flash memory requires an internal "charge pump" to burn data into the cells, forcing a 5ms to 10ms wait delay per write cycle. The MB85RC256 writes instantly at bus speed. It does not require a write-polling routine, completely eliminating data loss risk during sudden mid-write power failure.

**I²C Addressing Flexibility**

The device features a base binary slave address of 1010 (or 0x50). By hardwiring the address pins (A0, A1, A2) to either VCC or GND, you alter the final 3 bits of the address structure:

  * All pins to GND: **I²C Address is 0x50 (Default).**
  * All pins to VCC: I²C Address shifts to 0x57.


=== MB85RC256 Pinout ===
^ Pin Name ^ Function Type ^ Pin Description ^
| **VCC / VDD** | Power Input | Input power line. Connect to 3.3V or 5V depending on system logic. |
| **GND / VSS** | Power Ground | Common system ground for power and logic return. |
| **SDA** | I²C Logic Data | Serial Data line for bidirectional communication. Requires a pull-up resistor. |
| **SCL** | I²C Logic Clock | Serial Clock line driven by the I²C master device. |
| **WP** | Digital Input | **Write Protect** pin. Connect to VCC to lock memory against writes. Pulled down internally (write-enabled by default). |
| **A0** | Hardware Address | Sets bit 0 of the I²C slave address suffix. Connect to VCC or GND. |
| **A1** | Hardware Address | Sets bit 1 of the I²C slave address suffix. Connect to VCC or GND. |
| **A2** | Hardware Address | Sets bit 2 of the I²C slave address suffix. Connect to VCC or GND. |

===== I²C topics on lamaPLC =====
{{topic>i2c}}

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{{tag>communication i2c module memory FRAM 32KB MB85RC256 MB85RC256V}}
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