The **M95320-RMB3** is a high-performance, 32-Kbit (4 Kbyte) Electrically Erasable Programmable Read-Only Memory (EEPROM) manufactured by STMicroelectronics. It is designed for low-voltage applications and communicates via the Serial Peripheral Interface (SPI) bus. --- ### 1. Key Technical Specifications | Feature | Specification | | :--- | :--- | | **Memory Size** | 32 Kbit (4,096 bytes) | | **Interface** | SPI (Mode 0 and Mode 3) | | **Operating Voltage (Vcc)** | 1.8V to 5.5V | | **Max Clock Frequency** | 20 MHz (at 4.5V - 5.5V) | | **Page Size** | 32 Bytes | | **Operating Temperature** | -40°C to +125°C | | **Write Cycles** | More than 4 million cycles | | **Data Retention** | 200 Years | --- ### 2. Functional Components The device consists of several critical electronic blocks that manage data storage and retrieval: * **Memory Array:** Organized as 4096 words of 8 bits each. * **Status Register:** Controls the Write Inhibit features and indicates whether a Write cycle is in progress. * **Control Logic:** Decodes the 8-bit instructions sent via the SPI bus (e.g., READ, WRITE, WREN). * **Output Buffer:** Drives the Serial Data Output (Q) pin during read operations. * **Charge Pump:** An internal voltage multiplier that generates the high voltage required to program/erase the EEPROM cells from the low-voltage supply. --- ### 3. Pin Configuration and Package The **RMB3** suffix specifically refers to the **UFDFPN8 (MLP8)** package, which is an ultra-thin, fine-pitch dual flat no-lead package (2x3 mm). | Pin | Name | Description | | :--- | :--- | :--- | | 1 | **S#** | Chip Select (Active Low) | | 2 | **Q** | Serial Data Output | | 3 | **W#** | Write Control (Hardware protection) | | 4 | **Vss** | Ground | | 5 | **D** | Serial Data Input | | 6 | **C** | Serial Clock | | 7 | **HOLD#** | Pause communication without deselecting | | 8 | **Vcc** | Supply Voltage | --- ### 4. Application Logic (Pseudo-code Example) To read data from the M95320 using an MCU, you would typically follow this SPI sequence: ```cpp // Example: Reading a byte from address 0x01FF void read_eeprom(uint16_t address) { digitalWrite(CHIP_SELECT, LOW); // Select device SPI.transfer(0x03); // Send READ instruction SPI.transfer((address >> 8) & 0xFF); // Send High Address Byte SPI.transfer(address & 0xFF); // Send Low Address Byte uint8_t data = SPI.transfer(0x00); // Clock out the data digitalWrite(CHIP_SELECT, HIGH); // Deselect device } ``` ---