87C552 Single-Chip 8-Bit Microcontroller

Overview

The 87C552 is a high-performance, single-chip 8-bit microcontroller based on the 80C51 architecture. It combines a powerful CPU with integrated EPROM, RAM, and a rich set of peripherals, making it suitable for a wide range of embedded control applications. With its robust feature set and expandable memory, the 87C552 is designed to meet the demands of industrial, automotive, and consumer electronics applications.

Features

The 87C552 microcontroller offers a comprehensive set of features that enhance its performance and flexibility:

• 80C51 Central Processing Unit (CPU): High-performance 8-bit CPU with optimized instruction set for efficient operation.
• 8k × 8 EPROM: On-chip 8KB erasable programmable read-only memory for firmware storage, expandable externally up to 64KB.
• Additional 16-Bit Timer/Counter: Enhanced timing capabilities with an extra 16-bit timer/counter for precise event management.
• 256 Bytes of On-Chip RAM: Provides fast data access for temporary storage and stack operations.
• Four 8-Bit I/O Ports: Versatile input/output ports for interfacing with external devices and peripherals.
• Full-Duplex UART: Serial communication interface for asynchronous data transfer.
• Watchdog Timer: Enhances system reliability by resetting the microcontroller in case of software malfunctions.
• Power-Saving Modes: Idle and power-down modes to reduce energy consumption in battery-operated applications.
• Interrupt Structure: Multiple interrupt sources with priority levels for efficient event handling.

Applications

The 87C552 microcontroller is widely used in various embedded control applications, including:

• Industrial Automation: Motor control, sensor interfacing, and process monitoring.
• Automotive Systems: Engine management, dashboard controls, and safety systems.
• Consumer Electronics: Home appliances, remote controls, and smart devices.
• Medical Devices: Portable diagnostic equipment and patient monitoring systems.
• Communication Systems: Modems, routers, and peripheral controllers.

Electrical Characteristics

The 87C552 operates under the following electrical specifications:

• Supply Voltage (V_CC): 4.5V to 5.5V
• Operating Temperature Range: -40°C to +85°C (industrial grade)
• Power Consumption:
  • Active Mode: 25mA (typical at 12MHz)
  • Idle Mode: 6mA (typical at 12MHz)
  • Power-Down Mode: 50µA (typical)
• Clock Frequency: Up to 16MHz
• I/O Port Current: 10mA per pin (sink/source)
• EPROM Endurance: 1,000 erase/write cycles (minimum)

Package Information

The 87C552 is available in multiple package options to suit different design requirements:

• PLCC (Plastic Leaded Chip Carrier): 68-pin package with J-lead configuration for surface-mount applications.
• DIP (Dual In-Line Package): 40-pin through-hole package for prototyping and easy assembly.
• PQFP (Plastic Quad Flat Pack): 80-pin package for high-density PCB layouts.

Each package option provides robust mechanical and thermal performance, ensuring reliability in harsh operating environments.

Additional Technical Details

Memory Organization

The 87C552 features a well-organized memory architecture:

• Program Memory (EPROM): 8KB on-chip, expandable to 64KB via external memory interface.
• Data Memory (RAM): 256 bytes of on-chip RAM, with optional external expansion.
• Special Function Registers (SFRs): Dedicated registers for peripheral control and system configuration.

Timers and Counters

The microcontroller includes multiple timers for precise timing operations:

• Standard 16-Bit Timer/Counter: Compatible with the 80C51 timer architecture.
• Additional 16-Bit Timer/Counter: Provides extra flexibility for complex timing tasks.
• Programmable Counter Array (PCA): Supports PWM, capture/compare, and high-speed output modes.

Serial Communication

The built-in UART supports full-duplex serial communication with the following features:

• Baud rate programmable via timer.
• Framing error detection.
• Multiprocessor communication support.

Interrupt System

The 87C552 offers an advanced interrupt handling mechanism:

• Six interrupt sources with two priority levels.
• External interrupts with edge or level sensitivity.
• Fast interrupt response time for critical events.

Conclusion

The 87C552 is a versatile and powerful 8-bit microcontroller that combines the reliability of the 80C51 core with enhanced features such as expanded memory, additional timers, and robust I/O capabilities. Its wide operating voltage range, low power consumption, and flexible packaging options make it an excellent choice for demanding embedded applications across multiple industries.