X-Git-Url: http://git.joshuawise.com/fpgaboy.git/blobdiff_plain/eaec80f24007825c7abba2affd76f74d520ce4cd..31b9962d02cae0e935e392b688370504fd4125ff:/core/insn_alu_a.v

diff --git a/core/insn_alu_a.v b/core/insn_alu_a.v
index 14ccd76..5806438 100644
--- a/core/insn_alu_a.v
+++ b/core/insn_alu_a.v
@@ -32,9 +32,81 @@
 			`_F <= {`_F[7:5],`_A[7],`_F[3:0]};
 		end
 		`INSN_alu_RRA: begin
-			`_A <= {`_A[4],`_A[7:1]};
+			`_A <= {`_F[4],`_A[7:1]};
 			`_F <= {`_F[7:5],`_A[0],`_F[3:0]};
 		end
+		`INSN_alu_DAA: begin
+			if (`_F[6]) begin				
+				if (`_F[4]) begin
+					if(`_A[3:0] >= 4'h6 && `_A[7:4] >= 4'h6 && `_F[5]) begin
+						`_A <= `_A + 8'h9A;
+						`_F <= {((`_A + 8'h9A) == 8'b0), `_F[6:0]};
+					end
+					else begin
+						`_A <= `_A + 8'hA0;
+						`_F <= {((`_A + 8'hA0) == 8'b0), `_F[6:0]};
+					end
+				end
+				else begin
+					if(`_A[3:0] <= 4'h9 && `_A[7:4] <= 4'h9 && !`_F[5]) begin
+						`_F <= {(`_A == 8'b0), `_F[6:0]};
+					end
+					else begin
+						`_A <= `_A + 8'hFA;
+						`_F <= {((`_A + 8'hFA) == 8'b0), `_F[6:0]};
+					end
+				end
+			end
+			else begin
+				if (`_F[4]) begin
+					if(`_F[5]) begin
+						`_A <= `_A + 8'h66;
+						`_F <= {((`_A + 8'h66) == 8'b0), `_F[6:0]};
+					end
+					else if (`_A[3:0] > 4'h9) begin
+						`_A <= `_A + 8'h66;
+						`_F <= {((`_A + 8'h66) == 8'b0), `_F[6:0]};
+					end
+					else begin
+						`_A <= `_A + 8'h60;
+						`_F <= {((`_A + 8'h60) == 8'b0), `_F[6:0]};
+					end
+				end
+				else begin
+					if(`_F[5]) begin
+						if(`_A[7:4] > 4'h9) begin
+							`_A <= `_A + 8'h66;
+							`_F <= {((`_A + 8'h66) == 8'b0), `_F[6:5], 1'b1, `_F[3:0]};
+						end
+						else begin
+							`_A <= `_A + 8'h06;
+							`_F <= {((`_A + 8'h06) == 8'b0), `_F[6:0]};
+						end
+					end
+					else begin
+						if(`_A[3:0] > 4'h9) begin
+							if (`_A[7:4] > 4'h8) begin
+								`_A <= `_A + 8'h66;
+								`_F <= {((`_A + 8'h66) == 8'b0), `_F[6:5], 1'b1, `_F[3:0]};
+							end
+							else begin
+								`_A <= `_A + 8'h06;
+								`_F <= {((`_A + 8'h06) == 8'b0), `_F[6:0]};
+							end
+						end
+						else begin
+							if (`_A[7:4] > 4'h9) begin
+								`_A <= `_A + 8'h60;
+								`_F <= {((`_A + 8'h60) == 8'b0), `_F[6:5], 1'b1, `_F[3:0]};
+							end
+							else begin
+								`_F <= {(`_A == 8'b0), `_F[6:0]};
+							end
+						end
+					end
+				end
+			end
+		end
 		`INSN_alu_CPL: begin
 			`_A <= ~`_A;
 			`_F <= {`_F[7],1'b1,1'b1,`_F[4:0]};