Cyrix 486DX2/DX4 Processor
Processor Brief

• Desktop Processor
  • Features and Benefits
  • Technical Specifications

• Portable Processor
  • Features and Benefits
  • Technical Specifications

The Cyrix 486DX2/DX4 processors are designed for systems needing high performance and energy efficiency.The Cyrix 486DX2/DX4 processors are available in 100MHz, 80MHz, 75MHz, 66MHz, and 50MHz. The Cx486DX2/DX4's green features help exceed the requirements of energy-saving efforts such as the US EPA Energy Star program. The 486DX2/DX4 desktop features industry standard 486 compatibility, on-chip 8-KByte write-back cache, an integrated floating point unit, advanced power management, SMM, and high- speed 3-volt versions.

Portable systems based on the low power 3-volt Cx486DX2/DX4 processor are specifically designed for high performance. This product features low power, long battery life, 486 compatibility, 486DX2/DX4 socket and instruction set compatibility, on-chip 8-KByte write-back cache, low power 3-volt versions, advanced power management, system management mode (SMM), and an integrated floating point unit.

486DX2/DX4 Desktop Processors

Features and Benefits

Desktop Performance

Smart Green

Cyrix's high speed, 3-volt desktop CPUs consume less than half the power of standard 5-volt CPUs. With static circuitry, SMM, and automatic FPU power-down, the Cx486DX2/DX4 CPU's advanced power management features deliver additional power savings. The fully static design enables the CPU to operate and maintain a 0 MHz state (minimal power consumption) during idle times.

Product Options

• 66 and 80 MHz clock-doubled core CPU speeds
• 5- and 3-volt versions
• DX4
  • 100 and 75 MHz clock-tripled core CPU speeds
  • 3-volt version

Industry Standard 486 Compatibility

• 486DX2/DX4 socket and instruction set compatibility
• Fully compatible with DOS, Windows, OS/2, UNIX and Novell NetWare applications
• Standard 168-pin PGA package

On-Chip 8-KByte Write-Back Cache

• Up to 15% higher performance than write-through (80 MHz desktop platform)
• Industry-wide write-back chipset support
• Configurable as write-through or write-back

Integrated Floating Point Unit

• Executes 10% faster than 80486 DX

Advanced Power Management and SMM

• Fast SMI with separate memory space
• Fully static design permits dynamic clock control
• Software or hardware initiates low power suspend mode
• Automatic FPU power-down mode

High Speed 3-Volt Versions

• 66 and 80 MHz clock-doubled core CPU speeds (DX2)
• 100 and 75 MHz clock-tripled core CPU speeds (DX4)
• Consumes 50% less-power than 5-volt CPUs
• Advanced 3-volt CMOS process technology
• I/O buffers interface to either 3- or 5-volt logic

Cyrix 486DX2/DX4 Desktop Processor Technical Specifications

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Clock Speed          33, 40, 50, 2/50, 2/66 and 2/80 MHz; 3/75 and 3/100 MHz
Clocking             2x clock multiplier for DX2; 2x/3x multiplier for DX4
L1 Cache             8-KByte; write-back; 4-way associative; unified
                     instruction and data
Bus                  32-bit internal data bus; 32-bit address bus;
                     32-bit external data bus
Pin/Socket           168-pin PGA
Compatibility        Fully compatible with x86 software
Floating Point Unit  Fastest enhanced, integrated FPU with auto
                     powerdown
Voltage              5V or 3V core with 5V I/O tolerance for DX2
                     3V core with 5V I/O tolerance for DX4
Power Management     System Management Mode (SMM); hardware suspend;
                     Stop-clock capability; FPU auto-idle
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486DX2/DX4 Portable Processor

Features and Benefits

Low Power/Long Battery Life

Energy is also saved by taking advantage of advanced power management features such as static circuitry, SMM and automatic FPU power down. During idle times, the fully static design enables the CPU to operate and maintain a 0 MHz state which consumes less than 1% of full operating power.

Product Options

• DX2
  • 50 and 66 MHz clock-doubled core CPU speeds
  • 3-volt version
• DX4
  • 100 and 75 MHz clock-tripled core CPU speeds
  • 3-volt version

Industry Standard

• 486 Compatibility 486DX2/DX4 socket and instruction set compatible
• Fully compatible with DOS, Windows, OS/2, UNIX and Novell NetWare applications
• Standard 208-lead QFP package

On-Chip 8-KByte Write-Back Cache

• Up to 20% higher performance than write-through (66 MHz notebook platform)
• Industry-wide write-back chipset support
• Configurable as write-through or write-back

Low Power 3-Volt Versions

• Consumes 50% less power than 5-volt CPUs
• Advanced 3-volt CMOS process technology
• I/O buffers interface to either 3- or 5-volt logic

Advanced Power Management and SMM

• SMI with separate memory space
• Fully static design permits dynamic clock control
• Software or hardware initiates low power suspend mode
• Automatic FPU power-down mode

Integrated Floating Point Unit

• Executes 10% faster than 80486DX

Cyrix 486DX2/DX4 Portable Processor Technical Specifications

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Clock Speed          33, 40, 2/50, 2/66 and 2/80 MHz; 3/75 and 3/100 MHz
Clocking             2x clock multiplier for DX2; 2x/3x multiplier for DX4
L1 Cache             8-KByte; write-back; 4-way associative; unified
                     instruction and data
Bus                  32-bit internal data bus; 32-bit address bus;
                     32-bit external data bus
Pin/Socket           208-pin QFP
Compatibility        Fully compatible with x86 software
Floating Point Unit  Fastest enhanced, integrated FPU with auto
                     powerdown
Voltage              3V core with 5V I/O tolerance for DX2
                     3V core with 5V I/O tolerance for DX4
Power Management     System Management Mode (SMM); hardware suspend;
                     Stop-clock capability; FPU auto-idle
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