ST6255C

ST6255C 8-Bit Microcontroller Technical Summary

Overview

The ST6255C is a low-cost member of the ST62xx 8-bit HCMOS microcontroller family designed for low to medium complexity applications. This device features a robust architecture with integrated peripherals, making it suitable for a wide range of embedded control applications. The microcontroller combines high performance with low power consumption through its power-saving modes.

Key Features

• 8-bit ST6 Core Architecture: Optimized for embedded control applications
• Memory Organization:
  • Program Space: Up to 8KB ROM/EPROM
  • Data Space: 256 bytes RAM
  • EEPROM: Configurable memory space
  • Stack Space: Hardware stack implementation
• Clock System:
  • Main oscillator with configurable frequency
  • Low Frequency Auxiliary Oscillator (LFAO)
  • Oscillator Safe Guard feature
• Power Management:
  • WAIT mode for reduced power consumption
  • STOP mode for minimal power usage
• Integrated Peripherals:
  • Multiple I/O ports with configurable modes
  • Timer with multiple operating modes
  • Auto-Reload Timer (AR Timer)
  • 8-bit A/D Converter
  • Serial Peripheral Interface (SPI)
• System Protection:
  • Digital Watchdog Timer
  • Multiple reset sources (Power-on, Watchdog, LVD)

Applications

The ST6255C is suitable for a wide range of applications including:

• Industrial control systems
• Consumer electronics
• Automotive subsystems
• Home appliances
• Sensor interfaces
• Power management systems

Electrical Characteristics

Absolute Maximum Ratings

• Supply Voltage: -0.3V to +7.0V
• Input Voltage: -0.3V to VDD + 0.3V
• Operating Temperature: -40°C to +85°C
• Storage Temperature: -65°C to +150°C

Recommended Operating Conditions

• Supply Voltage: 3.0V to 6.0V
• Operating Temperature: -40°C to +85°C
• Clock Frequency: DC to 8MHz (main oscillator)

DC Characteristics

• Input Low Voltage: 0.3VDD max
• Input High Voltage: 0.7VDD min
• Output Low Voltage: 0.4V max (IOL = 10mA)
• Output High Voltage: VDD-0.7V min (IOH = -10mA)
• Power Supply Current:
  • Active Mode: 5mA typical at 8MHz
  • WAIT Mode: 1mA typical
  • STOP Mode: 10μA typical

AC Characteristics

• Instruction Cycle Time: 0.5μs at 8MHz
• Reset Pulse Width: 1μs min
• Interrupt Response Time: 2 instruction cycles

A/D Converter Characteristics

• Resolution: 8 bits
• Conversion Time: 20μs typical
• Input Voltage Range: 0V to VREF
• Integral Nonlinearity: ±1 LSB

Package Information

The ST6255C is available in multiple package options:

• DIP (Dual In-line Package):
  • 28-pin configuration
  • Body width: 300 mil
  • Lead pitch: 100 mil
• SOIC (Small Outline Integrated Circuit):
  • 28-pin configuration
  • Body width: 7.5mm
  • Lead pitch: 1.27mm
• PLCC (Plastic Leaded Chip Carrier):
  • 28-pin configuration
  • Body size: 11.43mm x 11.43mm
  • Lead pitch: 1.27mm

Memory Organization

The ST6255C features a sophisticated memory architecture:

Program Space

• Up to 8KB of ROM/EPROM
• Linear addressing space
• Supports in-circuit programming

Data Space

• 256 bytes of RAM
• Memory-mapped I/O registers
• Bank switching capability

Special Memory Features

• Data Window Register (DWR) for efficient memory access
• Data RAM/EEPROM Bank Register (DRBR) for memory expansion
• Configurable EEPROM space

Development Support

The ST6255C is supported by a comprehensive development ecosystem:

• In-circuit programming capability
• Option bytes for configuration
• EPROM erasing functionality
• Standard ST6 instruction set
• Multiple addressing modes

Ordering Information

The device is available in several variants:

• ST6255C: Standard version with ROM
• ST62T55C: EPROM version for development
• ST62E55C: EEPROM version

Each variant is available in multiple package options with different temperature ranges.