Start refactoring instructions.

[fpgaboy.git] / insn_ld_reg_imm8.v

diff --git a/insn_ld_reg_imm8.v b/insn_ld_reg_imm8.v
new file mode 100644 (file)
index 0000000..77768e0
--- /dev/null
+++ b/insn_ld_reg_imm8.v
@@ -0,0 +1,43 @@
+`ifdef EXECUTE
+       `INSN_LD_reg_imm8: begin
+               case (cycle)
+               0:      begin
+                               `EXEC_INC_PC;
+                               `EXEC_NEXTADDR_PCINC;
+                               rd <= 1;
+                       end
+               1:      begin
+                               `EXEC_INC_PC;
+                               if (opcode[5:3] == `INSN_reg_dHL) begin
+                                       address <= {registers[`REG_H], registers[`REG_L]};
+                                       wdata <= rdata;
+                                       rd <= 0;
+                                       wr <= 1;
+                               end else begin
+                                       `EXEC_NEWCYCLE;
+                               end
+                       end
+               2:      begin
+                               `EXEC_NEWCYCLE;
+                       end
+               endcase
+       end
+`endif
+
+`ifdef WRITEBACK
+       `INSN_LD_reg_imm8:
+               case (cycle)
+               0:      begin end
+               1:      case (opcode[5:3])
+                       `INSN_reg_A:    begin registers[`REG_A] <= rdata; end
+                       `INSN_reg_B:    begin registers[`REG_B] <= rdata; end
+                       `INSN_reg_C:    begin registers[`REG_C] <= rdata; end
+                       `INSN_reg_D:    begin registers[`REG_D] <= rdata; end
+                       `INSN_reg_E:    begin registers[`REG_E] <= rdata; end
+                       `INSN_reg_H:    begin registers[`REG_H] <= rdata; end
+                       `INSN_reg_L:    begin registers[`REG_L] <= rdata; end
+                       `INSN_reg_dHL:  begin /* Go off to cycle 2 */ end
+                       endcase
+               2:      begin end
+               endcase
+`endif