Overview
The X1241 device by XICOR is a Real Time Clock (RTC) integrated circuit, which includes clock/calendar functionality and CPU Supervisor with onboard EEPROM. The X1241 is designed for applications needing a reliable timekeeping system, alongside programmable monitoring and control capabilities.
Features
Real Time Clock and Calendar: Maintains accurate time with leap year correction and provisions for adjustments of shorter months and year 2000. It uses a low-cost 32.768kHz crystal and operates without loss of accuracy during read/write operations.
Memory: Equipped with 2 Kilobytes of EEPROM with a 64-byte page write mode and a 3-bit block lock for secure data storage, with single byte write and typical nonvolatile write cycle time of 5ms.
Watchdog Timer and Reset: Includes a selectable watchdog timer (with intervals of 1.75s, 750ms, 250ms, or off) to support system reliability and a programmable low voltage reset to safeguard system operations.
Power and Energy Efficiency: The X1241 features secondary power supply input with automatic switch-over during primary power failure. It maintains low power consumption with <1uA operating current and active currents of <3mA during programming and <400uA during data read.
Communication: Offers a 2-wire interface interoperable with I2C, capable of a 400kHz data transfer rate, and includes SCL and SDA pins for clocking data in and out of the device.
Packaging: Available in two compact form factors, the 8-lead SOIC and 8-lead TSSOP packages.
Operational Details
The Block Diagram indicates the internal components and their connections, showcasing the integration of timekeeping registers, frequency dividers, control logic, and EEPROM within the chip.
When powered, the X1241 automatically switches to a backup power supply (VBACK) if the primary supply (Vcc) drops below a threshold, ensuring uninterrupted operation. A reset output is also provided, signaling the host processor upon watchdog timeout or critical voltage drops.
Pin Configuration
The datasheet details the pins responsible for crystal connections and how the oscillator is expected to function with recommended configurations, highlighting Citizen CFS-206 as the recommended crystal. Pin descriptions include the functions of SCL and SDA for serial communication, the role of VBACK for backup power, and the RESET output characteristics.
Final Notes
Characteristics of the X1241, such as the voltage thresholds and timing specifications, are subject to change without notice according to the revision note (REV 1.1.3) dated February 13, 2001. This indicates that users should consult the most recent version of this datasheet before making design decisions.
References:
Chat: Powered By VoiceSphere
Pricing & Distributors: https://www.datasheets360.com/part/detail/x1241s8-2-7a/-7838423800229455225/
