ADSP-2185 Digital Signal Processor Technical Summary

Overview

The ADSP-2185 is a high-performance, single-chip microcomputer optimized for digital signal processing (DSP) and other numerically intensive applications. As part of the ADSP-2100 family, it combines an advanced DSP architecture with integrated memory and versatile system interfaces to deliver 33 MIPS sustained performance. With its 30 ns instruction cycle time and single-cycle execution capabilities, the ADSP-2185 is particularly well-suited for real-time signal processing applications requiring both high throughput and power efficiency.

This processor features 80K bytes of on-chip RAM, sophisticated computational units, and multiple interface options that enable flexible system designs with minimal external components. Its power management capabilities, including low-power idle modes and rapid wake-up from power-down, make it ideal for portable and power-sensitive applications.

Key Features

Performance Characteristics

• 30 ns instruction cycle time (33 MIPS sustained performance)
• Single-cycle instruction execution and context switching
• 3-bus architecture enables dual operand fetches every instruction cycle
• Multifunction instructions for optimized code density
• Advanced power management:
  • Power-down mode with low CMOS standby power
  • 100-cycle recovery from power-down condition
  • Low power dissipation in idle mode

Integration and Architecture

• ADSP-2100 family code compatible with instruction set extensions
• 80K bytes on-chip RAM configured as:
  • 16K words program memory RAM
  • 16K words data memory RAM
• Dual-purpose program memory for both instruction and data storage
• Independent computational units:
  • ALU (Arithmetic Logic Unit)
  • Multiplier/accumulator (24-bit result, 40-bit accumulator)
  • Barrel shifter
• Two independent data address generators
• Advanced program sequencer with zero-overhead looping
• Programmable 16-bit interval timer with prescaler

System Interfaces

• 16-bit internal DMA port for high-speed memory access (mode selectable)
• 4 MByte byte memory interface for data tables and program overlays
• 8-bit DMA to byte memory for transparent transfers (mode selectable)
• I/O memory interface with 2048 locations supporting parallel peripherals
• Programmable memory strobes and separate I/O memory space for glueless design
• Programmable wait state generation
• Two double-buffered serial ports with:
  • Companding hardware (μ-law/A-law)
  • Automatic data buffering
• Automatic booting from byte-wide external memory (e.g., EPROM)
• Six external interrupts
• 13 programmable flag pins for system signaling
• UART emulation capability through software SPORT reconfiguration
• ICE-Port™ emulator interface for in-system debugging

Applications

The ADSP-2185's combination of high performance, integrated memory, and flexible interfaces makes it suitable for a wide range of applications including:

• Audio signal processing and effects processing
• Speech recognition and synthesis systems
• Telecommunications equipment (modems, echo cancellation)
• Medical imaging and diagnostic equipment
• Industrial control and automation systems
• Military/aerospace signal processing
• Automotive sound and vibration analysis
• Consumer electronics (digital audio, advanced toys)
• Image processing and computer vision
• Biometric identification systems

Electrical Characteristics

Absolute Maximum Ratings

• Supply voltage (VDD): -0.3V to +7.0V
• Input voltage: -0.3V to VDD + 0.3V
• Operating temperature range: -40°C to +85°C (industrial)
• Storage temperature range: -65°C to +150°C

Recommended Operating Conditions

• Supply voltage: 3.0V to 3.6V (3.3V nominal)
• Operating temperature: -40°C to +85°C
• Input high voltage (VIH): 2.0V min (VDD = 3.0V)
• Input low voltage (VIL): 0.8V max (VDD = 3.0V)

Power Consumption

• Active mode (33 MIPS operation): 300 mW typical
• Idle mode: 60 mW typical
• Power-down mode: < 1 mW

Timing Characteristics

• Instruction cycle time: 30 ns (33.3 MHz)
• Clock input high/low time: 12 ns min
• Reset pulse width: 100 ns min
• Interrupt setup time: 5 ns min
• Memory access time: 15 ns max

Package Information

100-Lead Thin Quad Flat Pack (TQFP)

• Package dimensions: 14mm x 14mm body
• Lead pitch: 0.5mm
• Lead count: 100
• Package height: 1.2mm max
• Moisture sensitivity level (MSL): 3
• Recommended soldering profile:
  • Peak temperature: 260°C max
  • Time above 217°C: 60 seconds max

Pin Configuration

The 100-lead TQFP package organizes pins into functional groups:

• Power and ground pins (multiple VDD and GND pins for noise reduction)
• Clock and reset control pins
• External memory interface pins (address, data, control)
• DMA and I/O interface pins
• Serial port pins (two independent ports)
• Flag and interrupt pins
• Emulation and test pins

Design Considerations

Power Supply Decoupling

Proper decoupling is critical for stable operation:

• Use 0.1 μF ceramic capacitors placed close to each VDD pin
• Include bulk decoupling (10 μF tantalum or ceramic) near the package
• Separate analog and digital supply domains when applicable

Clock Generation

• Can be driven from crystal oscillator or external clock source
• Maintain clock signal integrity with proper termination
• Keep clock traces short and away from high-speed data lines

Thermal Management

• Maximum junction temperature: 125°C
• Thermal resistance (θJA): 45°C/W (still air)
• For high ambient temperatures or full performance operation:
  • Consider airflow cooling
  • Use thermal vias in PCB under package

Development Support

Software Tools

• Crosscore® Embedded Studio development environment
• VisualDSP++ development tools (legacy support)
• C/C++ compilers with DSP-specific optimizations
• Assembly language tools
• DSP libraries for common algorithms

Hardware Tools

• EZ-KIT Lite evaluation boards
• ICE-100B emulator for in-circuit debugging
• Third-party development system support