The MC146818ACP is a Real-Time Clock (RTC) plus RAM. Manufactured by Freescale Semiconductor - NXP, this device integrates a time-of-day clock, calendar, and static RAM in a single package. It provides accurate timekeeping and non-volatile data storage, even when the main system power is off.

Applications:

• Personal computers (PCs)
• Embedded systems requiring accurate timekeeping
• Data loggers
• Industrial control systems
• Point-of-sale (POS) terminals

Features:

• Real-time clock with hundredths-of-seconds, seconds, minutes, hours, day of the week, date, month, and year.
• Automatic leap year compensation.
• 50 bytes of general-purpose static RAM.
• Selectable crystal oscillator frequency (32.768 kHz).
• Alarm interrupt function.
• Periodic interrupt function.
• Battery backup input for continuous operation.
• Multiplexed bus for address and data.

Benefits:

• Provides accurate and reliable timekeeping for various applications.
• Non-volatile RAM allows for storage of critical system parameters and configuration data.
• Battery backup ensures continuous operation even during power outages.
• Alarm and periodic interrupt functions enable time-based event triggering.
• Simplified interface with microprocessors and microcontrollers.
• Reduces system complexity and component count.

Additional Details:

The MC146818ACP communicates with a host processor via a multiplexed address and data bus. It requires a 32.768 kHz crystal oscillator for accurate timekeeping. The device includes a battery backup input that allows it to maintain time and data even when the main system power is off. The RTC provides alarm and periodic interrupt functions that can be used to trigger events at specific times or intervals. The 50 bytes of static RAM can be used for general-purpose data storage. The device is available in a DIP package.