Scoreboarding - The Algorithm

The Algorithm

The detailed algorithm for the scoreboard control is described below:

function issue(op, dst, src1, src2) wait until (!Busy AND !Result); // FU can be any functional unit that can execute operation op Busy ← Yes; Op ← op; F_i ← dst; F_j ← src1; F_k ← src2; Q_j ← Result; Q_k ← Result; R_j ← not Q_j; R_k ← not Q_k; Result ← FU; function read_operands(FU) wait until (R_j AND R_k); R_j ← No; R_k ← No; function execute(FU) // Execute whatever FU must do function write_back(FU) wait until (f {(F_j≠F_i OR R_j=No) AND (F_k≠F_i OR R_k=No)}) foreach f do if Q_j=FU then R_j ← Yes; if Q_k=FU then R_k ← Yes; Result] ← 0; Busy ← No;