core/insn_incdec16.v

   1 `define INSN_INCDEC16           9'b000xxx011
   2
   3 `ifdef EXECUTE
   4         `INSN_INCDEC16: begin
   5                 case (cycle)
   6                 0:      case (opcode[5:4])
   7                         `INSN_reg16_BC: {tmp,tmp2} <= `_BC;
   8                         `INSN_reg16_DE: {tmp,tmp2} <= `_DE;
   9                         `INSN_reg16_HL: {tmp,tmp2} <= `_HL;
  10                         `INSN_reg16_SP: {tmp,tmp2} <= `_SP;
  11                         endcase
  12                 1:      begin
  13                                 `EXEC_INC_PC
  14                                 `EXEC_NEWCYCLE
  15                         end
  16                 endcase
  17         end
  18 `endif
  19
  20 `ifdef WRITEBACK
  21         `INSN_INCDEC16: begin
  22                 case (cycle)
  23                 0:      {tmp,tmp2} <= {tmp,tmp2} +
  24                                 (opcode[3] ? 16'hFFFF : 16'h0001);
  25                 1:      case (opcode[5:4])
  26                         `INSN_reg16_BC: `_BC <= {tmp,tmp2};
  27                         `INSN_reg16_DE: `_DE <= {tmp,tmp2};
  28                         `INSN_reg16_HL: `_HL <= {tmp,tmp2};
  29                         `INSN_reg16_SP: `_SP <= {tmp,tmp2};
  30                         endcase
  31                 endcase
  32         end
  33 `endif