Condition checking and scoreboard setting

• Issue step

  • Unit free, say Ua and no WAW
    

• Dispatch (Read operand )step

  • Rj and Rk must be free

• Execution step

  • At end ask for writing permission (no WAR)

• Write result

  • Check if Pi is an Fj, Fk(Rj , Rk= no) in preceding instrs.

• Issue step

  • Ua busy and record Fi,Fj,Fk
  • Record Qj, Qk and Rj,Rk
  • Record Pi = Ua

• Dispatch (Read operand) step

  
  

• Execution step

  
  

• Write result

  • For preceding instrs, if Qj(Qk) = Ua, set Rj(Rk) to yes
  • Ua free and Pi = 0

Previous slide

Next slide

Back to first slide

View graphic version