REAL-TIME CLOCK PLUS RAM(RTC) The MC146818AP is a Real-Time Clock (RTC) and CMOS RAM chip manufactured by Motorola. Below are its specifications, descriptions, and features:
### **Specifications:**
- **Manufacturer:** Motorola
- **Type:** Real-Time Clock (RTC) with CMOS RAM
- **Clock Accuracy:** Adjustable via external crystal oscillator
- **Timekeeping Functions:** Seconds, minutes, hours, day of week, date, month, year (with leap year compensation)
- **RAM Capacity:** 64 bytes (50 bytes general-purpose, 14 bytes for clock/control)
- **Supply Voltage:** Typically operates at **5V**
- **Interface:** Parallel (8-bit data bus)
- **Operating Temperature Range:** **0°C to 70°C** (commercial grade)
- **Package:** **24-pin DIP (Dual In-line Package)**
### **Descriptions:**
- The MC146818AP is a low-power CMOS device designed for real-time clock and calendar functions.
- It includes a battery backup feature to maintain timekeeping and RAM data during power loss.
- It is commonly used in early IBM PC/AT-compatible systems and embedded applications requiring timekeeping.
### **Features:**
- **Programmable Alarm:** Can trigger an interrupt at a specified time.
- **Square Wave Output:** Configurable frequency output (e.g., 1Hz, 32.768kHz).
- **Battery Backup Operation:** Maintains time and RAM data when main power is off.
- **Three Interrupt Sources:** Time update, alarm, and periodic interrupts.
- **Binary or BCD Time Representation:** Selectable format for timekeeping registers.
- **Low Power Consumption:** Optimized for battery-backed applications.
This information is based solely on Motorola's specifications for the MC146818AP.
