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Technical Summary: COP8ACC5 8-bit Microcontroller

Overview

The COP8ACC5 is a member of the COP8™ family of 8-bit microcontrollers from National Semiconductor. It is a fully static CMOS microcontroller designed for low-power, high-performance embedded applications. The device integrates a rich set of peripherals, including analog functions, timers, and serial communication interfaces, making it suitable for a wide range of industrial and consumer applications. With its versatile I/O options, power-saving modes, and robust instruction set, the COP8ACC5 is ideal for battery-operated and energy-efficient systems.

Key Features

• Analog Function Block: High-resolution A/D capabilities including an analog comparator with seven input multiplexers, a constant current source, and a V_CC/2 reference.
• 16-bit Capture Timer: Upcounter clocked from CKI with auto-reset on timer start-up.
• Quiet Design: Reduced radiated emissions for improved electromagnetic compatibility (EMC).
• Memory: 4096 bytes of on-board ROM and 128 bytes of on-board RAM.
• Peripheral Features:
  • Idle Timer
  • One 16-bit timer with two 16-bit registers supporting PWM, external event counting, and input capture modes.
  • Multi-Input Wake-Up (MIWU) with optional interrupts (4).
  • Watchdog and clock monitor logic.
  • MICROWIRE/PLUS™ serial I/O with programmable shift clock polarity.
• I/O Features:
  • Memory-mapped I/O.
  • Software-selectable I/O options (Push-Pull Output, Weak Pull-Up Input, High Impedance Input).
  • High-current outputs.
  • Schmitt Trigger inputs on ports G and L.
• CPU/Instruction Set Features:
  • 1µs instruction cycle time.
  • Eight multi-source vectored interrupts.
  • Versatile and easy-to-use instruction set.
  • 8-bit Stack Pointer (SP) with stack in RAM.
  • Two 8-bit Registers Indirect Data Memory Pointers (B and X).
• Power Efficiency:
  • Fully static CMOS design with low current drain (typically < 5 µA in HALT mode).
  • Two power-saving modes: HALT and IDLE.
  • Single supply operation (2.5V to 5.5V).
• Temperature Ranges: Commercial (0°C to +70°C) and Industrial (–40°C to +85°C).

Applications

The COP8ACC5 is well-suited for a variety of embedded control applications, including but not limited to:

• Battery Chargers: Leveraging its analog features and low-power modes for efficient energy management.
• Appliances: Home and industrial appliances requiring reliable control logic.
• Data Acquisition Systems: High-resolution analog measurements with integrated A/D functionality.
• Consumer Electronics: Remote controls, sensors, and portable devices.
• Industrial Automation: Timer-based control, event counting, and PWM-driven motor control.

Electrical Characteristics

The COP8ACC5 operates under the following electrical specifications:

• Supply Voltage: 2.5V to 5.5V.
• Power Consumption: Typically < 5 µA in HALT mode, optimized for battery-powered applications.
• Clock Speed: Supports a wide range of clock frequencies with a 1µs instruction cycle time.
• I/O Current: High-current outputs capable of driving LEDs and other peripherals directly.
• Analog Inputs: Seven multiplexed analog inputs with comparator functionality.

Package Information

The COP8ACC5 is available in multiple package options to suit different design requirements:

• 28-Pin Packages:
  • 28-pin DIP (Dual In-line Package).
  • 28-pin SO (Small Outline).
  • Provides 23 I/O pins for versatile connectivity.
• 20-Pin SO Package:
  • 20-pin Small Outline package.
  • Provides 15 I/O pins for space-constrained applications.

Development Support

National Semiconductor provides comprehensive development tools for the COP8ACC5, including:

• Emulation and OTP Devices: Prototyping and one-time programmable (OTP) variants for development and production.
• MetaLink Development System: Enables real-time emulation and full program debugging.
• iceMASTER™ Debugger: Advanced debugging capabilities for complex applications.

Block Diagram Overview

The COP8ACC5 features a modified Harvard architecture with the following key blocks:

• CPU Core: 8-bit ALU, program counter (PC), and control logic.
• Memory: 4KB ROM and 128B RAM.
• Timers: 16-bit Timer T1 (PWM/capture/event counting) and Idle Timer T0.
• Analog Block: Comparator, V_CC/2 reference, and current source.
• I/O Ports: Configurable ports with Schmitt Trigger inputs on select pins.
• Serial Interface: MICROWIRE/PLUS™ for synchronous communication.

Conclusion

The COP8ACC5 microcontroller combines performance, power efficiency, and a rich peripheral set, making it an excellent choice for embedded control applications. Its analog capabilities, flexible I/O, and low-power modes cater to demanding environments, from industrial automation to portable consumer devices. With robust development support and multiple packaging options, the COP8ACC5 offers designers a versatile and reliable solution for 8-bit embedded systems.