anchor.diff:        if (isSNaN(sV1) || isSNaN(sV2)) e.invalid_op = True;
         let fcsr = exception_to_fcsr(e);
   
  -      fa_driveResponse (res, fcsr);
         resultR     <= tagged Valid (tuple2 (res, fcsr));
         stateR      <= FBOX_RSP;
      endrule
  
positive.code:                         , exp:   dV1.exp
                          , sfd:   dV1.sfd};
        Bit #(64) res = pack (r1);
        fa_driveResponse (res, 0);
        resultR     <= tagged Valid (tuple2 (res, 0));
        stateR      <= FBOX_RSP;
     endrule
  
negative.code:       // stored, sign-extended as per the v2.2 of the spec
        Bit #(64) res = signExtend(pack(v));
        let fcsr = exception_to_fcsr(e);
        resultR     <= tagged Valid (tuple2 (res, fcsr));
        stateR      <= FBOX_RSP;
     endrule
  