X-Git-Url: http://git.joshuawise.com/fpgaboy.git/blobdiff_plain/2e642f1f5c3cb12c3a34983d9fbdd0141ca34931..4da100650a5d23c0cb3407c6fadbbebae68e5ed6:/GBZ80Core.v

diff --git a/GBZ80Core.v b/GBZ80Core.v
index fc77377..1bc8f78 100644
--- a/GBZ80Core.v
+++ b/GBZ80Core.v
@@ -37,6 +37,13 @@
 `define INSN_RST				8'b11xxx111
 `define INSN_RET				8'b110x1001	// 1 = RETI, 0 = RET
 `define INSN_CALL				8'b11001101
+`define INSN_JP_imm			8'b11000011
+`define INSN_JPCC_imm		8'b110xx010
+
+`define INSN_cc_NZ			2'b00
+`define INSN_cc_Z				2'b01
+`define INSN_cc_NC			2'b10
+`define INSN_cc_C				2'b11
 
 `define INSN_reg_A		3'b111
 `define INSN_reg_B		3'b000
@@ -423,6 +430,34 @@ module GBZ80Core(
 					end
 				endcase
 			end
+			`INSN_JP_imm,`INSN_JPCC_imm: begin
+				case (cycle)
+				0:	begin
+						`EXEC_INC_PC;
+						`EXEC_NEXTADDR_PCINC;
+						rd <= 1;
+					end
+				1:	begin
+						`EXEC_INC_PC;
+						`EXEC_NEXTADDR_PCINC;
+						rd <= 1;
+					end
+				2:	begin
+						if (!opcode[0]) 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
+				3:	begin
+						`EXEC_NEWCYCLE;
+					end
+				endcase
+			end
 			default:
 				$stop;
 			endcase
@@ -656,6 +691,15 @@ module GBZ80Core(
 					end
 				endcase
 			end
+			`INSN_JP_imm,`INSN_JPCC_imm: begin
+				case (cycle)
+				0:	begin /* type F */ end
+				1:	tmp <= rdata;	// tmp contains newpcl
+				2:	tmp2 <= rdata;	// tmp2 contains newpch
+				3:	{registers[`REG_PCH],registers[`REG_PCL]} <=
+						{tmp2,tmp};
+				endcase
+			end
 			default:
 				$stop;
 			endcase
@@ -663,155 +707,3 @@ module GBZ80Core(
 		end
 		endcase
 endmodule
-
-`timescale 1ns / 1ps
-module ROM(
-	input [15:0] address,
-	inout [7:0] data,
-	input clk,
-	input wr, rd);
-
-	reg [7:0] rom [2047:0];
-	initial $readmemh("rom.hex", rom);
-
-	wire decode = address[15:13] == 0;
-	wire [7:0] odata = rom[address[11:0]];
-	assign data = (rd && decode) ? odata : 8'bzzzzzzzz;
-	//assign data = rd ? odata : 8'bzzzzzzzz;
-endmodule
-
-module InternalRAM(
-	input [15:0] address,
-	inout [7:0] data,
-	input clk,
-	input wr, rd);
-	
-	reg [7:0] ram [8191:0];
-	
-	wire decode = (address >= 16'hC000) && (address < 16'hFE00);
-	reg [7:0] odata;
-	wire idata = data;
-	assign data = (rd && decode) ? odata : 8'bzzzzzzzz;
-	
-	always @(negedge clk)
-	begin
-		if (decode && rd)
-			odata <= ram[address[12:0]];
-		else if (decode && wr)
-			ram[address[12:0]] <= data;
-	end
-endmodule
-
-//module Switches(
-//	input [15:0] address,
-//	inout [7:0] data,
-//	input clk,
-//	input wr, rd,
-//	input [7:0] switches,
-//	output reg [7:0] ledout);
-	
-//	wire decode = address == 16'hFF51;
-//	reg [7:0] odata;
-//	wire idata = data;
-//	assign data = (rd && decode) ? odata : 8'bzzzzzzzz;
-	
-//	always @(negedge clk)
-//	begin
-//		if (decode && rd)
-//			odata <= switches;
-//		else if (decode && wr)
-//			ledout <= data;
-//	end
-//endmodule
-
-module CoreTop(
-	input iclk, xtal,
-	output wire [7:0] leds,
-	output serio,
-	output wire [3:0] digits,
-	output wire [7:0] seven);
-	
-	wire clk;
-	//IBUFG ibuf (.O(clk), .I(iclk));
-	
-	CPUDCM dcm (.CLKIN_IN(xtal), .CLKFX_OUT(clk));
-
-	wire [15:0] addr;
-	wire [7:0] data;
-	wire wr, rd;
-	
-	assign leds = iclk?{rd,wr,addr[5:0]}:data[7:0];
-
-	GBZ80Core core(
-		.clk(clk),
-		.busaddress(addr),
-		.busdata(data),
-		.buswr(wr),
-		.busrd(rd));
-	
-	ROM rom(
-		.address(addr),
-		.data(data),
-		.clk(clk),
-		.wr(wr),
-		.rd(rd));
-	
-	AddrMon amon(
-    .addr(addr), 
-    .clk(xtal), 
-    .digit(digits), 
-    .out(seven)
-    );
-	
-	assign serio = 0;
-endmodule
-
-module TestBench();
-	reg clk = 0;
-	wire [15:0] addr;
-	wire [7:0] data;
-	wire wr, rd;
-	
-//	wire [7:0] leds;
-//	wire [7:0] switches;
-	
-	always #10 clk <= ~clk;
-	GBZ80Core core(
-		.clk(clk),
-		.busaddress(addr),
-		.busdata(data),
-		.buswr(wr),
-		.busrd(rd));
-	
-	ROM rom(
-		.clk(clk),
-		.address(addr),
-		.data(data),
-		.wr(wr),
-		.rd(rd));
-	
-//	InternalRAM ram(
-//		.address(addr),
-//		.data(data),
-//		.clk(clk),
-//		.wr(wr),
-//		.rd(rd));
-
-//	wire serio;
-//	UART uart(
-//		.addr(addr),
-//		.data(data),
-//		.clk(clk),
-//		.wr(wr),
-//		.rd(rd),
-//		.serial(serio));
-	
-//	Switches sw(
-//		.clk(clk),
-//		.address(addr),
-//		.data(data),
-//		.wr(wr),
-//		.rd(rd),
-//		.switches(switches),
-//		.leds(leds));
-endmodule