The Microchip Technology Inc. 24LCS22A is a 256 x 8-bitdual-mode Electrically Erasable PROM (EEPROM). Thisdevice is designed for use in applications requiringstorage and serial transmission of configuration andcontrol information. Two modes of operation have beenimplemented: Transmit-Only mode (1 Kbit) andBidirectional mode (2 Kbit). Upon power-up, the devicewill be in the Transmit-Only mode, sending a serial bitstream of the memory array from 00h to 7Fh, clocked bythe VCLK pin. A valid high-to-low transition on the SCL pinwill cause the device to enter the Transition mode, andlook for a valid control byte on the I2C?Compatible bus. If it detects avalid control byte from the master, it will switch intoBidirectional mode, with byte selectable read/writecapability of the entire 2K memory array using SCL. If nocontrol byte is received, the device will revert to the Transmit-Only mode after it receives 128 consecutive VCLKpulses while the SCL pin is idle. The 24LCS22A is availablein standard 8-pin PDIP and SOIC packages. The24LCS22A features a flexible write-protect pin which isenabled by writing to address 7Fh (usually the checksumin VESA? applications.

   Single Supply with Operation Down to 2.5V

   Supports Enhanced EDID? (E-EDID?) 1.3

   Completely Implements DDC1?/DDC2? Interfacefor Monitor Identification, including Recoveryto DDC1

   2 Kbit Serial EEPROM Low-Power CMOSTechnology:

   2-Wire Serial Interface Bus, I2C? Compatible

   100 kHz (2.5V) and 400 kHz (5V) Compatibility

   Self-Timed Write Cycle (including Auto-Erase)

   Hardware Write-Protect Pin

   Page Write Buffer for up to Eight Bytes

   1,000,000 Erase Write Cycles

   Data Retention >200 years