The **M95320-RMB3G** is a high-performance, 32-Kbit serial SPI (Serial Peripheral Interface) EEPROM manufactured by STMicroelectronics. It is designed for low-voltage applications and is commonly found in automotive and industrial control systems. --- ### 1. Key Technical Specifications | Parameter | Specification | | :--- | :--- | | **Memory Size** | 32 Kbit (4,096 bytes) | | **Interface** | SPI (Mode 0 and Mode 3) | | **Operating Voltage** | 1.8V to 5.5V | | **Max Clock Frequency** | 20 MHz (at 4.5V - 5.5V) | | **Package Type** | UFDFPN8 (MLP8) | | **Temperature Range** | -40°C to +125°C | | **Write Cycles** | 4 Million cycles | | **Data Retention** | 200 Years | --- ### 2. Functional Description The device is organized as 4096 x 8 bits. It utilizes a high-speed SPI bus to communicate with a microcontroller. * **Instruction Set:** It supports standard SPI opcodes (WREN, WRDI, RDSR, WRSR, READ, WRITE). * **Write Protection:** Includes a Write Protect (`W`) pin and software-definable block protection bits (BP0, BP1) within the status register. * **Byte/Page Write:** Supports writing a single byte or a full page (up to 32 bytes) in one cycle. --- ### 3. Pinout Configuration (UFDFPN8) | Pin Number | Name | Description | | :--- | :--- | :--- | | 1 | **S#** | Chip Select (Active Low) | | 2 | **Q** | Serial Data Output | | 3 | **W#** | Write Protect | | 4 | **VSS** | Ground | | 5 | **D** | Serial Data Input | | 6 | **C** | Serial Clock | | 7 | **HOLD#** | Hold (Suspends communication) | | 8 | **VCC** | Supply Voltage | --- ### 4. Part Number Breakdown The suffix **RMB3G** provides specific manufacturing details: * **R**: Operating voltage range (1.8V to 5.5V). * **MB**: Package type (UFDFPN8 / Ultra Thin Fine Pitch Dual Flat No-lead). * **3**: Temperature range (Device tested/qualified for -40°C to +125°C). * **G**: ECOPACK2 (RoHS compliant and Halogen-free). --- ### 5. Application Example (C-like Pseudo Code) To write data to the memory, the microcontroller must first send the Write Enable (WREN) instruction. ```c // Example sequence to write a byte CS_Low(); // Select the chip SPI_Transfer(0x06); // Send WREN opcode CS_High(); // Deselect to trigger WREN CS_Low(); // Select the chip SPI_Transfer(0x02); // Send WRITE opcode SPI_Transfer(0x00); // Send Address High Byte SPI_Transfer(0x20); // Send Address Low Byte SPI_Transfer(0xAA); // Send Data (0xAA) CS_High(); // Deselect to start internal write cycle ```