-`define INSN_imm8_reg_A 3'b111
-`define INSN_imm8_reg_B 3'b000
-`define INSN_imm8_reg_C 3'b001
-`define INSN_imm8_reg_D 3'b010
-`define INSN_imm8_reg_E 3'b011
-`define INSN_imm8_reg_H 3'b100
-`define INSN_imm8_reg_L 3'b101
-`define INSN_imm8_reg_dHL 3'b110
+`define INSN_HALT 8'b01110110
+`define INSN_LD_HL_reg 8'b01110xxx
+`define INSN_LD_reg_HL 8'b01xxx110
+`define INSN_LD_reg_reg 8'b01xxxxxx
+`define INSN_reg_A 3'b111
+`define INSN_reg_B 3'b000
+`define INSN_reg_C 3'b001
+`define INSN_reg_D 3'b010
+`define INSN_reg_E 3'b011
+`define INSN_reg_H 3'b100
+`define INSN_reg_L 3'b101
+`define INSN_reg_dHL 3'b110