8-bit RISC VN801

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As its predecessor, SigmaK3, the microprocessor VN8_01 is targeted as a low-cost, high performance low power consumption 8-bit CPU employing a modified RISC architecture with separate instruction and data buses. This allows a simultaneous access to program and data memories. The 5-stage pipeline allows VN8_01 to perform 5 instructions at the same time, resulting in a net processing speed 5 times faster than a normal pipeline-less architecture. All instructions are executed in one system clock cycle, except branch instructions in 2 cycles.

Furthermore, a dedicated compiler is developed specially for VN8_01 in order to exploit VN8_01 pipeline architecture to optimize instruction arrangement. This also improves the microprocessor‘s performance.




  • CPU’s features
    • Harvard RISC 5-stage pipeline architecture
    • 37 instructions
    • 14-bit instruction width
    • Extensible instruction memory up to 64Kx14-bit
    • Power saving SLEEP mode
    • Synchronous design
  • Peripherals 
    • Interrupt controller: 8 interrupted sources
    • Four 8-bit bidirectional I/O ports
    • Timer0, Timer1, Timer2
    • Compare Capture PWM – Pulse-Width Modulation
    • USART
    • Watchdog Timer (8-bit)

Technical Characteristics

  • Process: TSMC 0.25um, 5 metal layers
  • Core voltage: 2.5V
  • PAD voltage: 3.3V
  • Core size: 460um x 46um
  • Chip size: 20 x 14 x 2.2 mm3.
  • Number of pins: 100
  • Maximum system clock speed: 100 MHz
  • Power consumption: 133 mW