The AT24C256 is a 256Kbit (32KB) I2C EEPROM by Microchip. It provides non-volatile storage accessible via I2C, with up to 8 devices on the same bus using address pins. Write cycles are limited to ~1 million.
| Pin | Name | Function | Type |
|---|---|---|---|
| 1 | A0 | I2C address bit 0 | I/O |
| 2 | A1 | I2C address bit 1 | I/O |
| 3 | A2 | I2C address bit 2 | I/O |
| 4 | GND | Ground | GND |
| 5 | SDA | I2C data | BUS |
| 6 | SCL | I2C clock | BUS |
| 7 | WP | Write protect, HIGH = protected | I/O |
| 8 | VCC | Supply voltage | PWR |