`timescale 1ns / 1ps
-module ROM(
+module SimROM(
input [15:0] address,
inout [7:0] data,
input clk,
reg rdlatch = 0;
reg [7:0] odata;
- // synthesis attribute ram_style of rom is block
- reg [7:0] rom [1023:0];
+ reg [7:0] rom [32767:0];
initial $readmemh("rom.hex", rom);
wire decode = address[15:13] == 0;
initial $readmemh("fpgaboot.hex", brom0);
initial $readmemh("gbboot.hex", brom1);
+
+`ifdef isim
+ initial romno <= 1;
+`endif
wire decode = address[15:8] == 0;
wire [7:0] odata = (romno == 0) ? brom0[addrlatch] : brom1[addrlatch];
parameter ADDR_PROGADDRM = 16'hFF61;
parameter ADDR_PROGADDRL = 16'hFF62;
parameter ADDR_PROGDATA = 16'hFF63;
+ parameter ADDR_MBC = 16'hFF64;
reg rdlatch = 0, wrlatch = 0;
reg [15:0] addrlatch = 0;
reg [22:0] progaddr;
+ reg [7:0] mbc_emul = 8'b00000101; // High bit is whether we're poking flash
+ // low 7 bits are the MBC that we are emulating
+
assign cr_nADV = 0; /* Addresses are always valid! :D */
assign cr_nCE = 0; /* The chip is enabled */
assign cr_nLB = 0; /* Lower byte is enabled */
wire decode = (addrlatch[15:14] == 2'b00) /* extrom */ || (addrlatch[15:13] == 3'b101) /* extram */ || (addrlatch == ADDR_PROGDATA);
+ reg [3:0] rambank = 0;
+ reg [8:0] rombank = 1;
+
assign cr_nOE = decode ? ~rdlatch : 1;
- assign cr_nWE = decode ? ~wrlatch : 1;
+ assign cr_nWE = (decode && ((addrlatch == ADDR_PROGDATA) || (mbc_emul[6:0] == 0) || (addrlatch[15:13] == 3'b101))) ? ~wrlatch : 1;
assign cr_DQ = (~cr_nOE) ? 16'bzzzzzzzzzzzzzzzz : {8'b0, datalatch};
- assign cr_A = (addrlatch[15:14] == 2'b00) ? /* extrom */ {9'b0,addrlatch[13:0]} :
- (addrlatch[15:13] == 3'b101) ? {1'b1, 9'b0, addrlatch[12:0]} :
+ assign cr_A = (addrlatch[15:14] == 2'b00) ? /* extrom, home bank */ {9'b0,addrlatch[13:0]} :
+ (addrlatch[15:14] == 2'b01) ? /* extrom, paged bank */ {rombank, addrlatch[13:0]} :
+ (addrlatch[15:13] == 3'b101) ? /* extram */ {1'b1, 5'b0, rambank, addrlatch[12:0]} :
(addrlatch == ADDR_PROGDATA) ? progaddr :
23'b0;
- reg [7:0] regbuf;
-
always @(posedge clk) begin
case (address)
ADDR_PROGADDRH: if (wr) progaddrh <= data;
ADDR_PROGADDRM: if (wr) progaddrm <= data;
ADDR_PROGADDRL: if (wr) progaddrl <= data;
ADDR_PROGDATA: if (rd || wr) begin
- progaddr <= {progaddrh[6:0], progaddrm[7:0], progaddr[7:0]};
- {progaddrh[6:0], progaddrm[7:0], progaddr[7:0]} <= {progaddrh[6:0], progaddrm[7:0], progaddr[7:0]} + 23'b1;
+ progaddr <= {progaddrh[6:0], progaddrm[7:0], progaddrl[7:0]};
+ {progaddrh[6:0], progaddrm[7:0], progaddrl[7:0]} <= {progaddrh[6:0], progaddrm[7:0], progaddrl[7:0]} + 23'b1;
+ end
+ ADDR_MBC: begin
+ mbc_emul <= data;
+ rambank <= 0;
+ rombank <= 1;
end
endcase
+
+ if (mbc_emul[6:0] == 5) begin
+ if ((address[15:12] == 4'h2) && wr)
+ rombank <= {rombank[8], data};
+ else if ((address[15:12] == 4'h3) && wr)
+ rombank <= {data[0], rombank[7:0]};
+ else if ((address[15:12] == 4'h4) && wr)
+ rambank <= data[3:0];
+ end
+
rdlatch <= rd;
wrlatch <= wr;
addrlatch <= address;
output wire cr_nADV, cr_nCE, cr_nOE, cr_nWE, cr_CRE, cr_nLB, cr_nUB, cr_CLK,
output wire [22:0] cr_A,
inout [15:0] cr_DQ,
+ input ps2c, ps2d,
`endif
output wire hs, vs,
output wire [2:0] r, g,
IBUFG iclkbuf(.O(xtalb), .I(xtal));
CPUDCM dcm (.CLKIN_IN(xtalb), .CLKFX_OUT(clk));
pixDCM pixdcm (.CLKIN_IN(xtalb), .CLKFX_OUT(vgaclk));
+ wire [7:0] ps2buttons;
`endif
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 irq, tmrirq, lcdcirq, vblankirq, btnirq;
wire [7:0] jaddr;
wire [1:0] state;
+ wire ack;
GBZ80Core core(
.clk(clk),
.bus1wr(wr[1]),
.bus1rd(rd[1]),
.irq(irq),
+ .irqack(ack),
.jaddr(jaddr),
.state(state));
.rd(rd[1]));
`ifdef isim
- ROM rom(
+ SimROM rom(
.address(addr[0]),
.data(data[0]),
.clk(clk),
.vgar(r),
.vgag(g),
.vgab(b));
+
+ wire [7:0] sleds;
+`ifdef isim
+ assign leds = sleds;
+`else
+ assign leds = sleds | ps2buttons;
+`endif
+ Switches sw(
+ .clk(clk),
+ .address(addr[0]),
+ .data(data[0]),
+ .wr(wr[0]),
+ .rd(rd[0]),
+ .ledout(sleds),
+ .switches(switches)
+ );
+
+`ifdef isim
+`else
+ PS2Button ps2(
+ .clk(clk),
+ .inclk(ps2c),
+ .indata(ps2d),
+ .buttons(ps2buttons)
+ );
+`endif
+ Buttons ass(
+ .core_clk(clk),
+ .addr(addr[0]),
+ .data(data[0]),
+ .wr(wr[0]),
+ .rd(rd[0]),
+ .int(btnirq),
+ `ifdef isim
+ .buttons(switches)
+ `else
+ .buttons(ps2buttons)
+ `endif
+ );
+
AddrMon amon(
.clk(clk),
.addr(addr[0]),
(state == 2'b10) ? 4'b1000 :
4'b0100) );
- Switches sw(
- .clk(clk),
- .address(addr[0]),
- .data(data[0]),
- .wr(wr[0]),
- .rd(rd[0]),
- .ledout(leds),
- .switches(switches)
- );
-
UART nouart ( /* no u */
.clk(clk),
.addr(addr[0]),
.lcdc(lcdcirq),
.tovf(tmrirq),
.serial(1'b0),
- .buttons(1'b0),
+ .buttons(btnirq),
.master(irq),
+ .ack(ack),
.jaddr(jaddr));
Soundcore sound(
git.joshuawise.com / fpgaboy.git / blobdiff