### Overview of M95256-RBN3TP The **M95256-RBN3TP** is a high-performance, 256-Kbit (32 Kbyte) Serial SPI (Serial Peripheral Interface) EEPROM manufactured by STMicroelectronics. It is designed for non-volatile data storage in applications requiring low voltage and low power consumption. --- ### Technical Specifications | Feature | Specification | | :--- | :--- | | **Memory Size** | 256 Kbit (32,768 x 8 bits) | | **Interface** | SPI (Mode 0 and Mode 3) | | **Clock Frequency** | Up to 5 MHz (at 1.8V - 5.5V) | | **Operating Voltage** | 1.8V to 5.5V | | **Operating Temperature** | -40°C to +125°C | | **Package Type** | TDFN8 (2x3 mm) / UFDFPN8 | | **Write Cycles** | More than 4 million cycles | | **Data Retention** | Over 200 years | --- ### Key Internal Components and Features 1. **Memory Array**: Organized as 32,768 bytes, segmented into 64-byte pages. This allows for efficient "Page Write" operations. 2. **SPI Interface Engine**: Handles four standard signals: * **S (Chip Select)**: Activates the device. * **D (Serial Data Input)**: Receives instructions and data. * **Q (Serial Data Output)**: Sends data out. * **C (Serial Clock)**: Synchronizes data transfer. 3. **Write Protection Logic**: * **W (Write Protect) Pin**: Provides hardware protection against unauthorized write operations. * **Status Register**: Includes block-protect bits (BP0, BP1) to lock specific portions of the memory via software. 4. **HOLD Mechanism**: The **HOLD** pin allows the CPU to pause serial communication without resetting the internal sequence, useful when sharing the SPI bus with other high-priority peripherals. --- ### Pin Configuration (TDFN8/UFDFPN8) ```text Top View +----------+ S | 1 8 | VCC Q | 2 7 | HOLD W | 3 6 | C VSS | 4 5 | D +----------+ ``` --- ### Functional Highlights * **Byte and Page Write**: You can write a single byte or a full page (64 bytes) in one cycle. The self-timed write cycle typically completes in **5 ms**. * **Deep Power-Down Mode**: The device can be put into a low-power state to conserve energy in battery-operated devices. * **Identification Page**: Includes an additional 64-byte page used to store sensitive application parameters (can be permanently locked). ---