X-Git-Url: http://git.joshuawise.com/fpgaboy.git/blobdiff_plain/e7fb589a21ee26ad897e03cbd0d7a647d9cd97e5..58d068d423c00a843a9f1a761503ed685a30a27c:/GBZ80Core.v

diff --git a/GBZ80Core.v b/GBZ80Core.v
index 1182b32..ec882da 100644
--- a/GBZ80Core.v
+++ b/GBZ80Core.v
@@ -146,9 +146,12 @@
 
 module GBZ80Core(
 	input clk,
-	output reg [15:0] busaddress,	/* BUS_* is latched on STATE_FETCH. */
-	inout [7:0] busdata,
-	output reg buswr, output reg busrd,
+	inout [15:0] bus0address,	/* BUS_* is latched on STATE_FETCH. */
+	inout [7:0] bus0data,
+	inout bus0wr, bus0rd,
+	inout [15:0] bus1address,	/* BUS_* is latched on STATE_FETCH. */
+	inout [7:0] bus1data,
+	inout bus1wr, bus1rd,
 	input irq, input [7:0] jaddr,
 	output reg [1:0] state);
 
@@ -167,7 +170,24 @@ module GBZ80Core(
 	reg [7:0] tmp, tmp2;			/* Generic temporary regs. */
 	
 	reg [7:0] buswdata;
-	assign busdata = buswr ? buswdata : 8'bzzzzzzzz;
+	wire [7:0] busdata;
+	
+	reg [15:0] busaddress;
+	reg buswr, busrd;
+	
+	reg bootstrap_enb;
+	
+	wire bus = ((busaddress[15:8] == 8'h00) && bootstrap_enb) || ((busaddress[15:7] == 9'b111111111) && (busaddress != 16'hFFFF));	/* 0 or 1 depending on which bus */
+		
+	assign bus0address = (bus == 0) ? busaddress : 16'bzzzzzzzzzzzzzzz;
+	assign bus1address = (bus == 1) ? busaddress : 16'bzzzzzzzzzzzzzzz;
+	assign bus0data = ((bus == 0) && buswr) ? buswdata : 8'bzzzzzzzz;
+	assign bus1data = ((bus == 1) && buswr) ? buswdata : 8'bzzzzzzzz;
+	assign busdata = (bus == 0) ? bus0data : bus1data;
+	assign bus0rd = (bus == 0) ? busrd : 1'bz;
+	assign bus1rd = (bus == 1) ? busrd : 1'bz;
+	assign bus0wr = (bus == 0) ? buswr : 1'bz;
+	assign bus1wr = (bus == 1) ? buswr : 1'bz;
 
 	reg ie, iedelay;
 
@@ -257,6 +277,7 @@ module GBZ80Core(
 		state <= `STATE_WRITEBACK;
 		cycle <= 0;
 		twobyte <= 0;
+		bootstrap_enb <= 1;
 	end
 
 	always @(posedge clk)