insn_add_hl.v

   1 `ifdef EXECUTE
   2         `INSN_ADD_HL: begin
   3                 case (cycle)
   4                 0:      case (opcode[5:4])
   5                         `INSN_reg16_BC: {tmp,tmp2} <= `_BC;
   6                         `INSN_reg16_DE: {tmp,tmp2} <= `_DE;
   7                         `INSN_reg16_HL: {tmp,tmp2} <= `_HL;
   8                         `INSN_reg16_SP: {tmp,tmp2} <= `_SP;
   9                         endcase
  10                 1:      begin
  11                                 `EXEC_INC_PC
  12                                 `EXEC_NEWCYCLE
  13                         end
  14                 endcase
  15         end
  16 `endif
  17
  18 `ifdef WRITEBACK
  19         `INSN_ADD_HL: begin
  20                 case (cycle)
  21                 0:      {tmp,tmp2} <= `_HL + {tmp,tmp2};
  22                 1:      begin
  23                                 `_F <=  { /* Z */ `_F[7],
  24                                           /* N */ 1'b0,
  25                                           /* H */ (({`_HL} + {tmp,tmp2}) & 16'h1000) ? 1'b1 : 1'b0,
  26                                           /* C */ (({1'b0,`_HL} + {1'b0,tmp,tmp2}) >> 16 == 1) ? 1'b1 : 1'b0,
  27                                           `_F[3:0]
  28                                         };
  29                                 `_HL <= {tmp, tmp2};
  30                         end
  31                 endcase
  32         end
  33 `endif