X-Git-Url: http://git.joshuawise.com/fpgaboy.git/blobdiff_plain/3ad960bdb71efcbb1dfd436163085da0d70eb699..df770340caf8ecd26a55179484edb507082bd5c6:/insn_jr-jrcc.v

diff --git a/insn_jr-jrcc.v b/insn_jr-jrcc.v
new file mode 100644
index 0000000..7a869b3
--- /dev/null
+++ b/insn_jr-jrcc.v
@@ -0,0 +1,38 @@
+`ifdef EXECUTE
+	`INSN_JR_imm,`INSN_JRCC_imm: begin
+		case (cycle)
+		0:	begin
+				`EXEC_INC_PC;
+				`EXEC_NEXTADDR_PCINC;
+				rd <= 1;
+			end
+		1: begin
+				`EXEC_INC_PC;
+				if (opcode[5]) begin	// i.e., JP cc,nn
+					/* We need to check the condition code to bail out. */
+					case (opcode[4:3])
+					`INSN_cc_NZ:	if (registers[`REG_F][7]) begin `EXEC_NEWCYCLE; end
+					`INSN_cc_Z:		if (~registers[`REG_F][7]) begin `EXEC_NEWCYCLE; end
+					`INSN_cc_NC:	if (registers[`REG_F][4]) begin `EXEC_NEWCYCLE; end
+					`INSN_cc_C:		if (~registers[`REG_F][4]) begin `EXEC_NEWCYCLE; end
+					endcase
+				end
+			end
+		2:	begin
+				`EXEC_NEWCYCLE;
+			end
+		endcase
+	end
+`endif
+
+`ifdef WRITEBACK
+	`INSN_JR_imm,`INSN_JRCC_imm: begin
+		case (cycle)
+		0:	begin /* type F */ end
+		1:	tmp <= rdata;
+		2:	{registers[`REG_PCH],registers[`REG_PCL]} <=
+				{registers[`REG_PCH],registers[`REG_PCL]} +
+				{tmp[7]?8'hFF:8'h00,tmp};
+		endcase
+	end
+`endif