X-Git-Url: http://git.joshuawise.com/fpgaboy.git/blobdiff_plain/00e30b4dd08f216cc9fe89295f575b9b7d0622b5..fa136d635a2e9dea677566536f71e69489dbb200:/GBZ80Core.v

diff --git a/GBZ80Core.v b/GBZ80Core.v
index 1d06b12..b7994ae 100644
--- a/GBZ80Core.v
+++ b/GBZ80Core.v
@@ -31,6 +31,8 @@
 `define INSN_PUSH_reg		8'b11xx0101
 `define INSN_POP_reg			8'b11xx0001
 `define INSN_LDH_AC			8'b111x0010	// Either LDH A,(C) or LDH (C),A
+`define INSN_LDx_AHL			8'b001xx010	// LDD/LDI A,(HL) / (HL),A
+
 `define INSN_reg_A		3'b111
 `define INSN_reg_B		3'b000
 `define INSN_reg_C		3'b001
@@ -275,7 +277,7 @@ module GBZ80Core(
 							rd <= 1;
 						end else begin
 							wr <= 1;
-							wdata <= {8'hFF,registers[`REG_A]};
+							wdata <= registers[`REG_A];
 						end
 					end
 				1: begin
@@ -284,6 +286,23 @@ module GBZ80Core(
 					end
 				endcase
 			end
+			`INSN_LDx_AHL: begin
+				case (cycle)
+				0: begin
+						address <= {registers[`REG_H],registers[`REG_L]};
+						if (opcode[3]) begin	// LDx A, (HL)
+							rd <= 1;
+						end else begin
+							wr <= 1;
+							wdata <= registers[`REG_A];
+						end
+					end
+				1:	begin
+						`EXEC_NEWCYCLE;
+						`EXEC_INC_PC;
+					end
+				endcase
+			end
 			default:
 				$stop;
 			endcase
@@ -434,6 +453,20 @@ module GBZ80Core(
 					end
 				endcase
 			end
+			`INSN_LDx_AHL: begin
+				case (cycle)
+				0:	cycle <= 1;
+				1:	begin
+						cycle <= 0;
+						if (opcode[3])
+							registers[`REG_A] <= rdata;
+						{registers[`REG_H],registers[`REG_L]} <=
+							opcode[4] ? // if set, LDD, else LDI
+							({registers[`REG_H],registers[`REG_L]} - 1) :
+							({registers[`REG_H],registers[`REG_L]} + 1);
+					end
+				endcase
+			end
 			endcase
 			state <= `STATE_FETCH;
 		end