// Ctrl5
    // input
    int16_t exS1 = cur.IDEX.s1;
    int16_t exS2 = cur.IDEX.s2;
    int16_t memRT = cur.EXMEM.rT;
    int16_t wbRT = cur.MEMWB.rT;
    int16_t endRT = cur.WBEND.rT;

    // MUXalu1
    if(exS1 == memRT && memRT != 0){
        ctrl.ctrl5MUXalu1 = cur.EXMEM.aluOutput;
    }
    else if(exS1 == wbRT && wbRT != 0){
        ctrl.ctrl5MUXalu1 = cur.MEMWB.rfWrite;
    }
    else if(exS1 == endRT && endRT != 0){
        ctrl.ctrl5MUXalu1 = cur.WBEND.writeData;
    }
    else{
        ctrl.ctrl5MUXalu1 = cur.IDEX.operand1;
    }
    alu.src1 = ctrl.ctrl5MUXalu1;

    // MUXalu2
    if(exS2 == memRT && memRT != 0){
        ctrl.ctrl5MUXalu2 = cur.EXMEM.aluOutput;
    }
    else if(exS2 == wbRT && wbRT != 0){
        ctrl.ctrl5MUXalu2 = cur.MEMWB.rfWrite;
    }
    else if(exS2 == endRT && endRT != 0){
        ctrl.ctrl5MUXalu2 = cur.WBEND.writeData;
    }
    else{
        ctrl.ctrl5MUXalu2 = cur.IDEX.operand2;
    }