REAL-TIME CLOCK PLUS RAM(RTC) The MC146818A is a real-time clock (RTC) and calendar component manufactured by Motorola (MOT). Below are its specifications, descriptions, and features based on factual information:
### **Manufacturer:**
- **Motorola (MOT)**
### **Specifications:**
- **Type:** Real-Time Clock (RTC) with CMOS technology
- **Clock Frequency:** 32.768 kHz (standard crystal frequency)
- **Timekeeping Accuracy:** Maintains timekeeping with minimal power consumption
- **Supply Voltage:** Typically operates at **5V**
- **Data Retention:** Battery-backed operation ensures data retention during power loss
- **Interface:** Parallel interface for communication with microprocessors
- **Calendar Functions:** Tracks seconds, minutes, hours, day, date, month, and year (including leap year compensation)
- **Alarm Function:** Programmable alarm with interrupt capability
- **Square Wave Output:** Configurable frequency output
### **Descriptions:**
- The MC146818A is a widely used RTC in early computer systems (e.g., IBM AT-compatible PCs).
- It includes **50 bytes of battery-backed RAM** for system configuration storage.
- The chip integrates a timekeeping circuit, oscillator, and power-sense circuitry for fail-safe operation.
### **Features:**
- **Low Power Consumption:** CMOS design ensures efficient battery operation.
- **Programmable Interrupts:** Supports alarms and periodic interrupts.
- **Binary or BCD Time Representation:** Configurable for different system requirements.
- **Battery Backup Support:** Maintains timekeeping during power outages.
- **Wide Operating Temperature Range:** Suitable for industrial applications.
This information is strictly based on the MC146818A's documented specifications and features.
