X-Git-Url: http://git.joshuawise.com/fpgaboy.git/blobdiff_plain/77ab69d7bb0902e6ebf0994159ed2205f8413e34..b057a5d6e6db6db06ae33703ca72cd235eec91d6:/core/insn_incdec16.v

diff --git a/core/insn_incdec16.v b/core/insn_incdec16.v
new file mode 100644
index 0000000..95e0d38
--- /dev/null
+++ b/core/insn_incdec16.v
@@ -0,0 +1,31 @@
+`ifdef EXECUTE
+	`INSN_INCDEC16: begin
+		case (cycle)
+		0:	case (opcode[5:4])
+			`INSN_reg16_BC:	{tmp,tmp2} <= `_BC;
+			`INSN_reg16_DE:	{tmp,tmp2} <= `_DE;
+			`INSN_reg16_HL:	{tmp,tmp2} <= `_HL;
+			`INSN_reg16_SP:	{tmp,tmp2} <= `_SP;
+			endcase
+		1:	begin
+				`EXEC_INC_PC
+				`EXEC_NEWCYCLE
+			end
+		endcase
+	end
+`endif
+
+`ifdef WRITEBACK
+	`INSN_INCDEC16: begin
+		case (cycle)
+		0:	{tmp,tmp2} <= {tmp,tmp2} +
+				(opcode[3] ? 16'hFFFF : 16'h0001);
+		1:	case (opcode[5:4])
+			`INSN_reg16_BC:	`_BC <= {tmp,tmp2};
+			`INSN_reg16_DE:	`_DE <= {tmp,tmp2};
+			`INSN_reg16_HL:	`_HL <= {tmp,tmp2};
+			`INSN_reg16_SP:	`_SP <= {tmp,tmp2};
+			endcase
+		endcase
+	end
+`endif