Technical Summary: 8742 Microcontroller

Overview

The 8742 is an advanced microcontroller designed to extend the capabilities of the Universal Peripheral Interface (UPI) concept, building upon the foundation laid by the 8741A. With enhanced memory and performance, the 8742 is tailored for more complex applications such as motor control, 80-column printers, and process control systems. Its architecture allows for seamless integration into upgraded 8741A designs while offering expanded functionality for new applications.

The 8742 is housed in a Dual In-line Package (DIP) and features a robust pin configuration that supports a wide range of peripheral interfacing and control tasks. Its block diagram highlights a well-organized internal structure, ensuring efficient data processing and control signal management.

Features

• Enhanced Memory Capacity: The 8742 offers expanded memory compared to the 8741A, enabling more complex program execution and data storage.
• High Performance: Optimized for speed and efficiency, the 8742 handles demanding tasks such as real-time motor control and high-speed printing.
• Universal Peripheral Interface (UPI): Retains compatibility with UPI-based systems while extending functionality for advanced applications.
• Versatile I/O Capabilities: Multiple input/output pins facilitate interfacing with a variety of peripherals and sensors.
• Robust Architecture: Designed for reliability in industrial and process control environments.
• DIP Packaging: The Dual In-line Package ensures ease of integration into existing circuit designs.

Applications

The 8742 microcontroller is suited for a broad range of applications, particularly those requiring enhanced performance and memory over the 8741A. Key application areas include:

• Motor Control Systems: Advanced motor control algorithms can be implemented thanks to the 8742's increased memory and processing power.
• Printers: Ideal for driving 80-column printers, where precision and speed are critical.
• Process Control: Used in industrial automation and process control systems to manage sensors, actuators, and other peripherals.
• Embedded Systems: Suitable for embedded applications requiring reliable and efficient microcontroller performance.
• Upgraded 8741A Designs: Provides a seamless upgrade path for systems originally designed around the 8741A.

Electrical Characteristics

The 8742 operates within specified electrical parameters to ensure reliable performance across its application range. Below are the key electrical characteristics:

Absolute Maximum Ratings

• Supply Voltage (Vcc): -0.5V to +7V
• Input Voltage (Vin): -0.5V to Vcc + 0.5V
• Operating Temperature Range: -40°C to +85°C
• Storage Temperature Range: -65°C to +150°C

Recommended Operating Conditions

• Supply Voltage (Vcc): 4.5V to 5.5V
• Operating Temperature: 0°C to +70°C
• Clock Frequency: Up to 12 MHz

DC Characteristics

• Input High Voltage (VIH): 2.0V min
• Input Low Voltage (VIL): 0.8V max
• Output High Voltage (VOH): 2.4V min @ IOH = -400µA
• Output Low Voltage (VOL): 0.45V max @ IOL = 1.6mA
• Power Consumption: 100mW typical

Package Information

The 8742 is available in a standard 40-pin Dual In-line Package (DIP), which is widely used in industrial and consumer electronics. The package dimensions and pin configuration are designed for easy integration into printed circuit boards (PCBs).

DIP Package Dimensions

• Package Type: 40-pin DIP
• Length: 52.32 mm (max)
• Width: 13.97 mm (max)
• Height: 4.44 mm (max)
• Pin Spacing: 2.54 mm (standard)

Pin Configuration

The 8742's pinout is designed to maximize functionality while maintaining compatibility with existing UPI systems. Below is a summary of the pin functions:

• Pins 1-8: Port 1 - General-purpose I/O or alternate functions.
• Pins 9-16: Port 2 - General-purpose I/O or control signals.
• Pins 17-20: Power and ground connections (Vcc, GND).
• Pins 21-28: Port 3 - Multiplexed address/data bus.
• Pins 29-40: Control and timing signals (ALE, PSEN, RD, WR, etc.).

Conclusion

The 8742 microcontroller represents a significant advancement over the 8741A, offering expanded memory, higher performance, and greater versatility for complex control tasks. Its robust electrical characteristics and DIP packaging make it an excellent choice for industrial, printing, and embedded applications. Whether upgrading an existing 8741A design or developing a new system, the 8742 provides the necessary features and reliability to meet demanding requirements.