## Technical Overview of M95640-RMB6TG The **M95640-RMB6TG** is a low-voltage, high-performance Serial Electrically Erasable Programmable Read-Only Memory (EEPROM) manufactured by STMicroelectronics. It is widely used for data storage in applications where space is limited and power consumption is critical. --- ### 1. Key Technical Specifications | Feature | Specification | | :--- | :--- | | **Memory Size** | 64 Kbit (8,192 x 8 bits) | | **Interface** | SPI (Serial Peripheral Interface) | | **Operating Voltage ($V_{CC}$)** | 1.8V to 5.5V | | **Max Clock Frequency** | 20 MHz (at 4.5V - 5.5V) | | **Package Type** | UFDFPN8 (Ultra-thin Fine pitch Dual Flat No-lead) | | **Operating Temperature** | -40°C to +85°C | | **Write Cycles** | 4 Million (more than typical 1M) | | **Data Retention** | 200 Years | --- ### 2. Functional Description The device communicates via a 4-wire SPI bus, consisting of: * **S (Chip Select):** Activates the device for communication. * **D (Serial Data Input):** Receives instructions, addresses, and data. * **Q (Serial Data Output):** Transfers data out of the device. * **C (Serial Clock):** Synchronizes the data transfer. #### Special Features: * **Byte and Page Write:** Supports writing a single byte or a full page (up to 32 bytes) in one cycle. * **Write Protection:** Includes a hardware Write Protect ($\bar{W}$) pin and software block protection via the Status Register. * **Hold Function:** The $\bar{HOLD}$ pin allows the communication to be paused without resetting the chip selection. --- ### 3. Pin Configuration (UFDFPN8) | Pin No. | Name | Function | | :--- | :--- | :--- | | 1 | $\bar{S}$ | Chip Select | | 2 | Q | Serial Data Output | | 3 | $\bar{W}$ | Write Protect | | 4 | $V_{SS}$ | Ground | | 5 | D | Serial Data Input | | 6 | C | Serial Clock | | 7 | $\bar{HOLD}$ | Hold Communication | | 8 | $V_{CC}$ | Supply Voltage | --- ### 4. Implementation Example (Pseudo-code) To read data from the M95640 using a microcontroller, the following sequence is generally followed: ```cpp // Basic SPI Read Sequence void read_eeprom(uint16_t address) { digitalWrite(CS_PIN, LOW); // Select the chip SPI.transfer(0x03); // Send READ instruction SPI.transfer((address >> 8)); // Send MSB of address SPI.transfer(address & 0xFF); // Send LSB of address uint8_t data = SPI.transfer(0x00);// Clock in the data digitalWrite(CS_PIN, HIGH); // Deselect the chip } ``` ---