Shift Register & Counter

• A variety of shift registers are available.

  • Example: SR8RLED = Shift Register, 8 bits, Load, Enable, BI-directional

• Shift Register function is determined by inputs:

  • Example: add clock enable using EC pin

• Libraries support a wide variety of fast and efficient counters

  • Counters offer trade-offs between speed, utilization, and complexity
  • Example: LogiBlox counter styles
    • Binary: predictable outputs, uses carry logic
    • Johnson: fastest practical counter, uses few Flip-Flops
    • LFSR: fast & dense, but pseudo-random outputs
    • One-Hot: useful for generating series of enables
    • Carry Chain: High speed and utilization
  • Most synthesis tools select a component based on the design, or the designer can instantiate a component using LogiBLOX.

이전 슬라이드

다음 슬라이드

첫 슬라이드로 이동

그래픽 버전 보기