From: Joshua Wise <joshua@rebirth.joshuawise.com>
Date: Sun, 4 May 2008 07:05:06 +0000 (-0400)
Subject: Dual bus processor
X-Git-Url: http://git.joshuawise.com/fpgaboy.git/commitdiff_plain/91c74a3f7409b5ac9bdbd46fbff13c513b19bc9c?ds=sidebyside

Dual bus processor
---

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)
diff --git a/Makefile b/Makefile
index 3a508ae..4b401d0 100644
--- a/Makefile
+++ b/Makefile
@@ -10,15 +10,15 @@ VLOGS_ALL = $(VLOGS) insn_call-callcc.v insn_incdec16.v insn_jr-jrcc.v \
 	insn_ldm8_a.v insn_ldm16_a.v insn_ldbcde_a.v insn_alu_ext.v \
 	insn_bit.v insn_two_byte.v insn_incdec_reg8.v
 
-all: CoreTop_rom.svf CoreTop_diag.svf CoreTop_bootrom.svf CoreTop.twr
+all: CoreTop.svf CoreTop.twr
 
 sim: CoreTop_isim.exe
 
-CoreTop.ngc: CoreTop.xst CoreTop.prj $(VLOGS_ALL)
+CoreTop.ngc: CoreTop.xst CoreTop.prj $(VLOGS_ALL) rom.mem
 	xst -ifn CoreTop.xst -ofn CoreTop.syr
 
 CoreTop.ngd: CoreTop.ngc foo.bmm CoreTop.ucf
-	ngdbuild -dd _ngo -uc CoreTop.ucf -nt timestamp -bm "foo.bmm" -p xc3s500e-fg320-5 "CoreTop.ngc" CoreTop.ngd
+	ngdbuild -dd _ngo -uc CoreTop.ucf -nt timestamp -p xc3s500e-fg320-5 "CoreTop.ngc" CoreTop.ngd
 
 CoreTop_map.ncd: CoreTop.ngd
 	map -p xc3s500e-fg320-5 -cm area -pr off -k 4 -c 100 -o CoreTop_map.ncd CoreTop.ngd CoreTop.pcf
@@ -63,10 +63,7 @@ parsim: CoreTop_isim_par.exe
 %.mem: %.bin mashrom
 	./mashrom < $< > $@
 
-CoreTop_%.bit: %.mem CoreTop.bit foo_bd.bmm
-	data2mem -bm foo_bd.bmm -bd $< -bt CoreTop.bit -o b $@
-
-CoreTop_%.svf: CoreTop_%.bit impact.cmd
+CoreTop.svf: CoreTop.bit impact.cmd
 	sed -e s/XXX/$(subst .bit,,$<)/ < impact.cmd > tmp.cmd
 	impact -batch tmp.cmd
 
diff --git a/System.v b/System.v
index cdcee09..4c5f85b 100644
--- a/System.v
+++ b/System.v
@@ -6,16 +6,30 @@ module ROM(
 	input clk,
 	input wr, rd);
 
+	// synthesis attribute ram_style of rom is block
 	reg [7:0] rom [1023:0];
 	initial $readmemh("rom.hex", rom);
 
 	wire decode = address[15:13] == 0;
 	wire [7:0] odata = rom[address[10:0]];
 	assign data = (rd && decode) ? odata : 8'bzzzzzzzz;
-	//assign data = rd ? odata : 8'bzzzzzzzz;
 endmodule
 
-module MiniRAM(			/* XXX will need to go INSIDE the CPU for when we do DMA */
+module BootstrapROM(
+	input [15:0] address,
+	inout [7:0] data,
+	input clk,
+	input wr, rd);
+
+	reg [7:0] rom [255:0];
+	initial $readmemh("bootstrap.hex", rom);
+
+	wire decode = address[15:8] == 0;
+	wire [7:0] odata = rom[address[7:0]];
+	assign data = (rd && decode) ? odata : 8'bzzzzzzzz;
+endmodule
+
+module MiniRAM(
 	input [15:0] address,
 	inout [7:0] data,
 	input clk,
@@ -125,9 +139,9 @@ module CoreTop(
 	pixDCM pixdcm (.CLKIN_IN(xtalb), .CLKFX_OUT(vgaclk));
 `endif
 
-	wire [15:0] addr;	
-	wire [7:0] data;
-	wire wr, rd;
+	wire [15:0] addr [1:0];
+	wire [7:0] data [1:0];
+	wire wr [1:0], rd [1:0];
 	
 	wire irq, tmrirq, lcdcirq, vblankirq;
 	wire [7:0] jaddr;
@@ -135,31 +149,42 @@ module CoreTop(
 	
 	GBZ80Core core(
 		.clk(clk),
-		.busaddress(addr),
-		.busdata(data),
-		.buswr(wr),
-		.busrd(rd),
+		.bus0address(addr[0]),
+		.bus0data(data[0]),
+		.bus0wr(wr[0]),
+		.bus0rd(rd[0]),
+		.bus1address(addr[1]),
+		.bus1data(data[1]),
+		.bus1wr(wr[1]),
+		.bus1rd(rd[1]),
 		.irq(irq),
 		.jaddr(jaddr),
 		.state(state));
 	
+	BootstrapROM brom(
+		.address(addr[1]),
+		.data(data[1]),
+		.clk(clk),
+		.wr(wr[1]),
+		.rd(rd[1]));
+	
 	ROM rom(
-		.address(addr),
-		.data(data),
+		.address(addr[0]),
+		.data(data[0]),
 		.clk(clk),
-		.wr(wr),
-		.rd(rd));
+		.wr(wr[0]),
+		.rd(rd[0]));
 	
 	wire lcdhs, lcdvs, lcdclk;
 	wire [2:0] lcdr, lcdg;
 	wire [1:0] lcdb;
 	
 	LCDC lcdc(
-		.addr(addr),
-		.data(data),
 		.clk(clk),
-		.wr(wr),
-		.rd(rd),
+		.addr(addr[0]),
+		.data(data[0]),
+		.wr(wr[0]),
+		.rd(rd[0]),
 		.lcdcirq(lcdcirq),
 		.vblankirq(vblankirq),
 		.lcdclk(lcdclk),
@@ -184,8 +209,8 @@ module CoreTop(
 		.vgab(b));
 	
 	AddrMon amon(
-		.addr(addr), 
 		.clk(clk), 
+		.addr(addr[0]),
 		.digit(digits), 
 		.out(seven),
 		.freeze(buttons[0]),
@@ -196,55 +221,55 @@ module CoreTop(
 			                   4'b0100) );
 	 
 	Switches sw(
-		.address(addr),
-		.data(data),
 		.clk(clk),
-		.wr(wr),
-		.rd(rd),
+		.address(addr[0]),
+		.data(data[0]),
+		.wr(wr[0]),
+		.rd(rd[0]),
 		.ledout(leds),
 		.switches(switches)
 		);
 
 	UART nouart (	/* no u */
-		.clk(clk), 
-		.wr(wr), 
-		.rd(rd), 
-		.addr(addr), 
-		.data(data), 
+		.clk(clk),
+		.addr(addr[0]),
+		.data(data[0]),
+		.wr(wr[0]),
+		.rd(rd[0]),
 		.serial(serio)
 		);
 
 	InternalRAM ram(
-		.address(addr),
-		.data(data),
 		.clk(clk),
-		.wr(wr),
-		.rd(rd)
+		.address(addr[0]),
+		.data(data[0]),
+		.wr(wr[0]),
+		.rd(rd[0])
 		);
 	
 	MiniRAM mram(
-		.address(addr),
-		.data(data),
 		.clk(clk),
-		.wr(wr),
-		.rd(rd)
+		.address(addr[1]),
+		.data(data[1]),
+		.wr(wr[1]),
+		.rd(rd[1])
 		);
 
 	Timer tmr(
 		.clk(clk),
-		.wr(wr),
-		.rd(rd),
-		.addr(addr),
-		.data(data),
+		.addr(addr[0]),
+		.data(data[0]),
+		.wr(wr[0]),
+		.rd(rd[0]),
 		.irq(tmrirq)
 		);
 	
 	Interrupt intr(
 		.clk(clk),
-		.rd(rd),
-		.wr(wr),
-		.addr(addr),
-		.data(data),
+		.addr(addr[0]),
+		.data(data[0]),
+		.wr(wr[0]),
+		.rd(rd[0]),
 		.vblank(vblankirq),
 		.lcdc(lcdcirq),
 		.tovf(tmrirq),
@@ -255,90 +280,10 @@ module CoreTop(
 	
 	Soundcore sound(
 		.core_clk(clk),
-		.rd(rd),
-		.wr(wr),
-		.addr(addr),
-		.data(data),
+		.addr(addr[0]),
+		.data(data[0]),
+		.rd(rd[0]),
+		.wr(wr[0]),
 		.snd_data_l(soundl),
 		.snd_data_r(soundr));
 endmodule
-
-`ifdef verilator
-`else
-module TestBench();
-	reg clk = 1;
-	wire [15:0] addr;
-	wire [7:0] data;
-	wire wr, rd;
-	
-	wire irq, tmrirq;
-	wire [7:0] jaddr;
-	
-	wire [7:0] leds;
-	wire [7:0] switches;
-	
-	always #62 clk <= ~clk;
-	GBZ80Core core(
-		.clk(clk),
-		.busaddress(addr),
-		.busdata(data),
-		.buswr(wr),
-		.busrd(rd),
-		.irq(irq),
-		.jaddr(jaddr));
-	
-	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));
-	
-	Timer tmr(
-		.clk(clk),
-		.wr(wr),
-		.rd(rd),
-		.addr(addr),
-		.data(data),
-		.irq(tmrirq));
-	
-	Interrupt intr(
-		.clk(clk),
-		.rd(rd),
-		.wr(wr),
-		.addr(addr),
-		.data(data),
-		.vblank(0),
-		.lcdc(0),
-		.tovf(tmrirq),
-		.serial(0),
-		.buttons(0),
-		.master(irq),
-		.jaddr(jaddr));
-	
-	Switches sw(
-		.clk(clk),
-		.address(addr),
-		.data(data),
-		.wr(wr),
-		.rd(rd),
-		.switches(switches),
-		.ledout(leds));
-endmodule
-`endif
diff --git a/oldrom.asm b/oldrom.asm
new file mode 100644
index 0000000..1504c71
--- /dev/null
+++ b/oldrom.asm
@@ -0,0 +1,70 @@
+	SECTION "a",HOME
+
+main:
+	ld a, $FF	; Note that we are alive.
+	ld [$FF51],a
+	
+	ld sp, $DFF0
+	
+	ld hl, $DF81
+	ld a, $80
+	ld [hl], a
+
+	ld c, $07
+	ld a, $04	;start timer, 4.096KHz
+	ld [c], a
+;diqs:	ei
+;	ld a, $80
+;	ld c, $51
+;	ld [c], a
+;	jr diqs
+	call irqhand
+	ei
+coqs: jr coqs
+
+	section "Diq", HOME[$38]
+fuqed:
+	di
+	jr fuqed
+
+	section "fuq",HOME[$100]
+irqhand:
+	PUSH AF
+	PUSH BC
+	PUSH DE
+	PUSH HL
+	
+	xor a
+	ld c, $0F	; ack the irq
+	ld [c], a
+	
+	ld a, $41	; print A
+	call putc
+	
+	ld hl, $DF81
+	inc [hl]
+	ld a, [hl]
+	ld c, $51
+	ld [c], a
+
+
+	POP HL
+	POP DE
+	POP BC
+	POP AF
+	RETI
+	db $18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE
+	db $18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE
+	db $18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE
+
+putc:
+	ld b, 0
+	ld c, $50
+	push af
+.waitport:
+	ld a,[c]
+	cp b
+	jr nz,.waitport
+	pop af
+	ld [c],a
+	ret
diff --git a/rom.asm b/rom.asm
deleted file mode 100644
index 1504c71..0000000
--- a/rom.asm
+++ /dev/null
@@ -1,70 +0,0 @@
-	SECTION "a",HOME
-
-main:
-	ld a, $FF	; Note that we are alive.
-	ld [$FF51],a
-	
-	ld sp, $DFF0
-	
-	ld hl, $DF81
-	ld a, $80
-	ld [hl], a
-
-	ld c, $07
-	ld a, $04	;start timer, 4.096KHz
-	ld [c], a
-;diqs:	ei
-;	ld a, $80
-;	ld c, $51
-;	ld [c], a
-;	jr diqs
-	call irqhand
-	ei
-coqs: jr coqs
-
-	section "Diq", HOME[$38]
-fuqed:
-	di
-	jr fuqed
-
-	section "fuq",HOME[$100]
-irqhand:
-	PUSH AF
-	PUSH BC
-	PUSH DE
-	PUSH HL
-	
-	xor a
-	ld c, $0F	; ack the irq
-	ld [c], a
-	
-	ld a, $41	; print A
-	call putc
-	
-	ld hl, $DF81
-	inc [hl]
-	ld a, [hl]
-	ld c, $51
-	ld [c], a
-
-
-	POP HL
-	POP DE
-	POP BC
-	POP AF
-	RETI
-	db $18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE
-	db $18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE
-	db $18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE
-
-putc:
-	ld b, 0
-	ld c, $50
-	push af
-.waitport:
-	ld a,[c]
-	cp b
-	jr nz,.waitport
-	pop af
-	ld [c],a
-	ret
diff --git a/rom.asm b/rom.asm
new file mode 120000
index 0000000..2dfb2b3
--- /dev/null
+++ b/rom.asm
@@ -0,0 +1 @@
+bootrom.asm
\ No newline at end of file