83C520

DS87C520/DS83C520 High-Speed 8051-Compatible Microcontroller Technical Summary

Overview

The DS87C520/DS83C520 is a high-performance, 8051-compatible microcontroller featuring a redesigned processor core that eliminates wasted clock and memory cycles. This architectural improvement allows the device to execute instructions significantly faster than standard 8051 implementations while maintaining full compatibility with the 8051 instruction set and pinout. With enhanced memory options, flexible clocking, and advanced features like dual data pointers, this microcontroller is ideal for applications requiring both 8051 compatibility and improved performance.

Key Features

• 80C52 Compatibility
  • Full 8051 pin and instruction set compatibility
  • Four 8-bit I/O ports for versatile interfacing
  • Three 16-bit timer/counters for precise timing operations
  • 256 bytes of scratchpad RAM for fast data access
• Enhanced Memory Architecture
  • 16KB of on-chip program memory
  • 1KB of additional on-chip SRAM dedicated for MOVX operations
  • ROMSIZE feature allowing dynamic selection of internal ROM size (0-16KB)
  • Full external memory map accessibility
• High-Speed Performance
  • 4-clock machine cycle (vs. 12-clock standard 8051)
  • Operating frequency from DC to 33MHz
  • Single-cycle instruction execution in just 121ns
  • Dual data pointer for improved memory access efficiency
  • Variable length MOVX for interfacing with both fast and slow peripherals

Applications

The DS87C520/DS83C520 is suitable for a wide range of embedded applications, including:

• Industrial control systems
• Automotive electronics
• Medical devices
• Communication equipment
• Consumer electronics
• Security systems
• Embedded networking devices
• Data acquisition systems

The microcontroller's combination of high-speed operation, flexible memory configuration, and 8051 compatibility makes it particularly valuable in applications requiring upgrades from legacy 8051 designs or needing to interface with existing 8051-based systems.

Electrical Characteristics

Absolute Maximum Ratings

• Supply Voltage (Vcc): -0.5V to +6.0V
• Input Voltage (any pin): -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: Commercial (0°C to +70°C) or Industrial (-40°C to +85°C)
• Clock Frequency: DC to 33MHz

DC Characteristics

• Input Low Voltage (VIL): -0.5V to 0.2Vcc-0.1V
• Input High Voltage (VIH): 0.2Vcc+0.9V to Vcc+0.5V
• Output Low Voltage (VOL): 0.45V max (IOL = 1.6mA)
• Output High Voltage (VOH): Vcc-0.7V min (IOH = -60μA)
• Power Supply Current: 25mA typical at 33MHz

AC Characteristics

• Machine Cycle Time: 121ns minimum at 33MHz
• Address Valid to ALE Low: 10ns
• ALE Pulse Width: 20ns
• Port 0 Float to Address Valid: 10ns
• RD Pulse Width: 60ns
• Data Valid After RD Low: 35ns
• Data Hold After RD High: 0ns

Package Information

The DS87C520/DS83C520 is available in several package options to accommodate different application requirements:

40-Pin Dual Inline Package (DIP)

• Package Type: PDIP
• Dimensions: 52.32mm x 13.97mm
• Pin Spacing: 2.54mm
• Row Spacing: 15.24mm
• Lead Material: Alloy 42
• Lead Finish: Matte Tin

44-Pin Plastic Leaded Chip Carrier (PLCC)

• Package Type: PLCC
• Dimensions: 16.51mm x 16.51mm
• Lead Count: 44
• Lead Pitch: 1.27mm
• JEDEC Standard: MO-047

44-Pin Thin Quad Flat Pack (TQFP)

• Package Type: TQFP
• Dimensions: 10mm x 10mm
• Body Thickness: 1.0mm
• Lead Pitch: 0.8mm
• Lead Count: 44
• JEDEC Standard: MO-220

Memory Organization

The DS87C520/DS83C520 features a sophisticated memory architecture that provides flexibility for various application requirements:

Program Memory

• 16KB of on-chip ROM (DS87C520) or EPROM (DS83C520)
• ROMSIZE feature allows software-configurable internal ROM size from 0 to 16KB
• Supports external program memory expansion up to 64KB
• Boot block capability for external FLASH programming

Data Memory

• 256 bytes of internal RAM (standard 8051 memory space)
• 1KB of additional on-chip SRAM accessible via MOVX instructions
• Supports external data memory expansion up to 64KB
• Dual data pointer improves block memory operations

Special Features

• Clock Doubler: Optional clock doubler for higher performance when needed
• Power Management: Multiple power-saving modes including Idle and Power Down
• Security Features: Program memory lock bits for code protection
• Watchdog Timer: Built-in watchdog timer for system reliability
• Serial Port: Full-duplex UART compatible with standard 8051 serial port

Development Support

The DS87C520/DS83C520 is supported by a comprehensive development ecosystem:

• Standard 8051 development tools and compilers
• In-circuit emulation support
• Flash programming utilities
• Evaluation boards available
• Application notes and reference designs

Ordering Information

The device is available in several variants to meet different application needs:

• DS87C520: Factory-programmed ROM version
• DS83C520: EPROM version for development and prototyping
• Temperature range options: Commercial (0°C to +70°C) and Industrial (-40°C to +85°C)
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