The **95320-R** is a specific variant of the **M95320** series, which is a popular **32 Kbit (4,096 x 8-bit) Serial SPI Bus EEPROM** (Electrically Erasable Programmable Read-Only Memory). It is manufactured primarily by STMicroelectronics. --- ### 1. Key Technical Specifications | Feature | Specification | | :--- | :--- | | **Memory Size** | 32 Kbit (4,096 Bytes) | | **Interface** | SPI (Serial Peripheral Interface) | | **Clock Frequency** | Up to 5 MHz (at 1.8V) to 20 MHz (at 5V) | | **Supply Voltage (Vcc)** | 1.8V to 5.5V (Standard for "-R" suffix) | | **Write Cycles** | 1,000,000+ cycles | | **Data Retention** | 40 - 100 Years | | **Operating Temp** | -40°C to +85°C | --- ### 2. Understanding the "-R" Suffix In STMicroelectronics nomenclature, the suffix provides critical information regarding the operating voltage: * **-R**: Indicates the device operates over a wide voltage range of **1.8V to 5.5V**. * This makes it ideal for battery-powered or low-power handheld devices. --- ### 3. Pinout Configuration The 95320-R usually comes in small packages like SO8, TSSOP8, or UFDFPN8. The standard pin mapping is: | Pin | Name | Description | | :--- | :--- | :--- | | **1** | **S#** | Chip Select (Active Low) | | **2** | **Q** | Serial Data Output (MISO) | | **3** | **W#** | Write Protect | | **4** | **Vss** | Ground | | **5** | **D** | Serial Data Input (MOSI) | | **6** | **C** | Serial Clock (SCK) | | **7** | **HOLD#** | Pause Serial Communication | | **8** | **Vcc** | Supply Voltage | --- ### 4. Common Use Cases The 95320-R is widely used in automotive, industrial, and consumer electronics to store: * **Calibration Data:** Sensors and measurement tools. * **Configuration Settings:** User preferences in home appliances. * **Automotive Modules:** Frequently found in Airbag modules (SRS), Odometers (Dashboards), and Immobilizers for storing crash data or mileage. * **Firmware Parameters:** Storing small amounts of code or lookup tables. --- ### 5. Implementation Example (C++ Pseudo-code) To read from the 95320-R using a microcontroller: ```cpp // Define SPI commands for M95320 #define READ_CMD 0x03 #define WRITE_CMD 0x02 #define WREN_CMD 0x06 // Write Enable void readEEPROM(uint16_t address) { digitalWrite(CS_PIN, LOW); // Select Chip SPI.transfer(READ_CMD); // Send Read OpCode SPI.transfer(address >> 8); // Send High Address Byte SPI.transfer(address & 0xFF); // Send Low Address Byte uint8_t data = SPI.transfer(0); // Read Result digitalWrite(CS_PIN, HIGH); // Deselect Chip } ```