System.v

   1
   2 `timescale 1ns / 1ps
   3 module SimROM(
   4         input [15:0] address,
   5         inout [7:0] data,
   6         input clk,
   7         input wr, rd);
   8
   9         reg rdlatch = 0;
  10         reg [7:0] odata;
  11
  12         reg [7:0] rom [32767:0];
  13         initial $readmemh("rom.hex", rom);
  14
  15         wire decode = address[15:13] == 0;
  16         always @(posedge clk) begin
  17                 rdlatch <= rd && decode;
  18                 odata <= rom[address[10:0]];
  19         end
  20         assign data = rdlatch ? odata : 8'bzzzzzzzz;
  21 endmodule
  22
  23 module BootstrapROM(
  24         input [15:0] address,
  25         inout [7:0] data,
  26         input clk,
  27         input wr, rd);
  28
  29         reg rdlatch = 0;
  30         reg [7:0] addrlatch = 0;
  31         reg romno = 0, romnotmp = 0;
  32         reg [7:0] brom0 [255:0];
  33         reg [7:0] brom1 [255:0];
  34
  35         initial $readmemh("fpgaboot.hex", brom0);
  36         initial $readmemh("gbboot.hex", brom1);
  37
  38 `ifdef isim
  39         initial romno <= 1;
  40 `endif
  41
  42         wire decode = address[15:8] == 0;
  43         wire [7:0] odata = (romno == 0) ? brom0[addrlatch] : brom1[addrlatch];
  44         always @(posedge clk) begin
  45                 rdlatch <= rd && decode;
  46                 addrlatch <= address[7:0];
  47                 if (wr && decode) romnotmp <= data[0];
  48                 if (rd && address == 16'h0000) romno <= romnotmp;       /* Latch when the program restarts. */
  49         end
  50         assign data = rdlatch ? odata : 8'bzzzzzzzz;
  51 endmodule
  52
  53 module MiniRAM(
  54         input [15:0] address,
  55         inout [7:0] data,
  56         input clk,
  57         input wr, rd);
  58
  59         reg [7:0] ram [127:0];
  60
  61         wire decode = (address >= 16'hFF80) && (address <= 16'hFFFE);
  62         reg rdlatch = 0;
  63         reg [7:0] odata;
  64         assign data = rdlatch ? odata : 8'bzzzzzzzz;
  65
  66         always @(posedge clk)
  67         begin
  68                 rdlatch <= rd && decode;
  69                 if (decode)             // This has to go this way. The only way XST knows how to do
  70                 begin                   // block ram is chip select, write enable, and always
  71                         if (wr)         // reading. "else if rd" does not cut it ...
  72                                 ram[address[6:0]] <= data;
  73                         odata <= ram[address[6:0]];
  74                 end
  75         end
  76 endmodule
  77
  78 module CellularRAM(
  79         input clk,
  80         input [15:0] address,
  81         inout [7:0] data,
  82         input wr, rd,
  83         output wire cr_nADV, cr_nCE, cr_nOE, cr_nWE, cr_CRE, cr_nLB, cr_nUB, cr_CLK,
  84         output wire st_nCE, st_nRST,
  85         output wire [22:0] cr_A,
  86         inout [15:0] cr_DQ);
  87
  88         parameter ADDR_PROGADDRH = 16'hFF60;
  89         parameter ADDR_PROGADDRM = 16'hFF61;
  90         parameter ADDR_PROGADDRL = 16'hFF62;
  91         parameter ADDR_PROGDATA = 16'hFF63;
  92         parameter ADDR_PROGFLASH = 16'hFF65;
  93         parameter ADDR_MBC = 16'hFF64;
  94
  95         reg rdlatch = 0, wrlatch = 0;
  96         reg [15:0] addrlatch = 0;
  97         reg [7:0] datalatch = 0;
  98
  99         reg [7:0] progaddrh, progaddrm, progaddrl;
 100
 101         reg [22:0] progaddr;
 102
 103         reg [7:0] mbc_emul = 8'b00000101;       // High bit is whether we're poking flash
 104                                                 // low 7 bits are the MBC that we are emulating
 105
 106         assign cr_nADV = 0;     /* Addresses are always valid! :D */
 107         assign cr_nCE = ~(addrlatch != ADDR_PROGFLASH); /* The chip is enabled */
 108         assign cr_nLB = 0;      /* Lower byte is enabled */
 109         assign cr_nUB = 0;      /* Upper byte is enabled */
 110         assign cr_CRE = 0;      /* Data writes, not config */
 111         assign cr_CLK = 0;      /* Clock? I think not! */
 112
 113         assign st_nRST = 1;     /* Keep the strataflash out of reset. */
 114         assign st_nCE = ~(addrlatch == ADDR_PROGFLASH);
 115
 116         wire decode = (addrlatch[15:14] == 2'b00) /* extrom */ || (addrlatch[15:13] == 3'b101) /* extram */ || (addrlatch == ADDR_PROGDATA) || (addrlatch == ADDR_PROGFLASH);
 117
 118         reg [3:0] rambank = 0;
 119         reg [8:0] rombank = 1;
 120
 121         assign cr_nOE = decode ? ~rdlatch : 1;
 122         assign cr_nWE = (decode && ((addrlatch == ADDR_PROGDATA) || (addrlatch == ADDR_PROGFLASH) || (mbc_emul[6:0] == 0) || (addrlatch[15:13] == 3'b101))) ? ~wrlatch : 1;
 123
 124         assign cr_DQ = (~cr_nOE) ? 16'bzzzzzzzzzzzzzzzz : {8'b0, datalatch};
 125         assign cr_A = (addrlatch[15:14] == 2'b00) ? /* extrom, home bank */ {9'b0,addrlatch[13:0]} :
 126                         (addrlatch[15:14] == 2'b01) ? /* extrom, paged bank */ {rombank, addrlatch[13:0]} :
 127                         (addrlatch[15:13] == 3'b101) ? /* extram */ {1'b1, 5'b0, rambank, addrlatch[12:0]} :
 128                         ((addrlatch == ADDR_PROGDATA) || (addrlatch == ADDR_PROGFLASH)) ? progaddr :
 129                         23'b0;
 130
 131         always @(posedge clk) begin
 132                 case (address)
 133                 ADDR_PROGADDRH: if (wr) progaddrh <= data;
 134                 ADDR_PROGADDRM: if (wr) progaddrm <= data;
 135                 ADDR_PROGADDRL: if (wr) progaddrl <= data;
 136                 ADDR_PROGDATA:  if (rd || wr) begin
 137                                         progaddr <= {progaddrh[6:0], progaddrm[7:0], progaddrl[7:0]};
 138                                         {progaddrh[6:0], progaddrm[7:0], progaddrl[7:0]} <= {progaddrh[6:0], progaddrm[7:0], progaddrl[7:0]} + 23'b1;
 139                                 end
 140                 ADDR_PROGFLASH: if (rd || wr) begin
 141                                         progaddr <= {progaddrh[6:0], progaddrm[7:0], progaddrl[7:0]};
 142                                         {progaddrh[6:0], progaddrm[7:0], progaddrl[7:0]} <= {progaddrh[6:0], progaddrm[7:0], progaddrl[7:0]} + 23'b1;
 143                                 end
 144                 ADDR_MBC:       begin
 145                                         mbc_emul <= data;
 146                                         rambank <= 0;
 147                                         rombank <= 1;
 148                                 end
 149                 endcase
 150
 151                 if (mbc_emul[6:0] == 5) begin
 152                         if ((address[15:12] == 4'h2) && wr)
 153                                 rombank <= {rombank[8], data};
 154                         else if ((address[15:12] == 4'h3) && wr)
 155                                 rombank <= {data[0], rombank[7:0]};
 156                         else if ((address[15:12] == 4'h4) && wr)
 157                                 rambank <= data[3:0];
 158                 end
 159
 160                 rdlatch <= rd;
 161                 wrlatch <= wr;
 162                 addrlatch <= address;
 163                 datalatch <= data;
 164         end
 165
 166         assign data = (rdlatch && decode) ?
 167                                 (addrlatch == ADDR_PROGADDRH) ? progaddrh :
 168                                 (addrlatch == ADDR_PROGADDRM) ? progaddrm :
 169                                 (addrlatch == ADDR_PROGADDRL) ? progaddrl :
 170                                 cr_DQ
 171                         : 8'bzzzzzzzz;
 172 endmodule
 173
 174 module InternalRAM(
 175         input [15:0] address,
 176         inout [7:0] data,
 177         input clk,
 178         input wr, rd);
 179
 180         // synthesis attribute ram_style of ram is block
 181         reg [7:0] ram [8191:0];
 182
 183         wire decode = (address >= 16'hC000) && (address <= 16'hFDFF);   /* This includes echo RAM. */
 184         reg [7:0] odata;
 185         reg rdlatch = 0;
 186         assign data = rdlatch ? odata : 8'bzzzzzzzz;
 187
 188         always @(posedge clk)
 189         begin
 190                 rdlatch <= rd && decode;
 191                 if (decode)             // This has to go this way. The only way XST knows how to do
 192                 begin                   // block ram is chip select, write enable, and always
 193                         if (wr)         // reading. "else if rd" does not cut it ...
 194                                 ram[address[12:0]] <= data;
 195                         odata <= ram[address[12:0]];
 196                 end
 197         end
 198 endmodule
 199
 200 module Switches(
 201         input [15:0] address,
 202         inout [7:0] data,
 203         input clk,
 204         input wr, rd,
 205         input [7:0] switches,
 206         output reg [7:0] ledout = 0);
 207
 208         wire decode = address == 16'hFF51;
 209         reg [7:0] odata;
 210         reg rdlatch = 0;
 211         assign data = rdlatch ? odata : 8'bzzzzzzzz;
 212
 213         always @(posedge clk)
 214         begin
 215                 rdlatch <= rd && decode;
 216                 if (decode && rd)
 217                         odata <= switches;
 218                 else if (decode && wr)
 219                         ledout <= data;
 220         end
 221 endmodule
 222
 223 `ifdef isim
 224 module Dumpable(input [2:0] r, g, input [1:0] b, input hs, vs, vgaclk);
 225 endmodule
 226 `endif
 227
 228 module CoreTop(
 229 `ifdef isim
 230         output reg vgaclk = 0,
 231         output reg clk = 0,
 232 `else
 233         input xtal,
 234         input [7:0] switches,
 235         input [3:0] buttons,
 236         output wire [7:0] leds,
 237         output serio,
 238         input serin,
 239         output wire [3:0] digits,
 240         output wire [7:0] seven,
 241         output wire cr_nADV, cr_nCE, cr_nOE, cr_nWE, cr_CRE, cr_nLB, cr_nUB, cr_CLK, st_nCE, st_nRST,
 242         output wire [22:0] cr_A,
 243         inout [15:0] cr_DQ,
 244         input ps2c, ps2d,
 245 `endif
 246         output wire hs, vs,
 247         output wire [2:0] r, g,
 248         output wire [1:0] b,
 249         output wire soundl, soundr);
 250
 251 `ifdef isim
 252         always #62 clk <= ~clk;
 253         always #100 vgaclk <= ~vgaclk;
 254
 255         Dumpable dump(r,g,b,hs,vs,vgaclk);
 256
 257         wire [7:0] leds;
 258         wire serio;
 259         wire serin = 1;
 260         wire [3:0] digits;
 261         wire [7:0] seven;
 262         wire [7:0] switches = 8'b0;
 263         wire [3:0] buttons = 4'b0;
 264 `else
 265         wire xtalb, clk, vgaclk;
 266         IBUFG iclkbuf(.O(xtalb), .I(xtal));
 267         CPUDCM dcm (.CLKIN_IN(xtalb), .CLKFX_OUT(clk));
 268         pixDCM pixdcm (.CLKIN_IN(xtalb), .CLKFX_OUT(vgaclk));
 269         wire [7:0] ps2buttons;
 270 `endif
 271
 272         wire [15:0] addr [1:0];
 273         wire [7:0] data [1:0];
 274         wire wr [1:0], rd [1:0];
 275
 276         wire irq, tmrirq, lcdcirq, vblankirq, btnirq;
 277         wire [7:0] jaddr;
 278         wire [1:0] state;
 279         wire ack;
 280
 281         GBZ80Core core(
 282                 .clk(clk),
 283                 .bus0address(addr[0]),
 284                 .bus0data(data[0]),
 285                 .bus0wr(wr[0]),
 286                 .bus0rd(rd[0]),
 287                 .bus1address(addr[1]),
 288                 .bus1data(data[1]),
 289                 .bus1wr(wr[1]),
 290                 .bus1rd(rd[1]),
 291                 .irq(irq),
 292                 .irqack(ack),
 293                 .jaddr(jaddr),
 294                 .state(state));
 295
 296         BootstrapROM brom(
 297                 .address(addr[1]),
 298                 .data(data[1]),
 299                 .clk(clk),
 300                 .wr(wr[1]),
 301                 .rd(rd[1]));
 302
 303 `ifdef isim
 304         SimROM rom(
 305                 .address(addr[0]),
 306                 .data(data[0]),
 307                 .clk(clk),
 308                 .wr(wr[0]),
 309                 .rd(rd[0]));
 310 `else
 311         CellularRAM cellram(
 312                 .address(addr[0]),
 313                 .data(data[0]),
 314                 .clk(clk),
 315                 .wr(wr[0]),
 316                 .rd(rd[0]),
 317                 .cr_nADV(cr_nADV),
 318                 .cr_nCE(cr_nCE),
 319                 .cr_nOE(cr_nOE),
 320                 .cr_nWE(cr_nWE),
 321                 .cr_CRE(cr_CRE),
 322                 .cr_nLB(cr_nLB),
 323                 .cr_nUB(cr_nUB),
 324                 .cr_CLK(cr_CLK),
 325                 .cr_A(cr_A),
 326                 .cr_DQ(cr_DQ),
 327                 .st_nCE(st_nCE),
 328                 .st_nRST(st_nRST));
 329 `endif
 330
 331         wire lcdhs, lcdvs, lcdclk;
 332         wire [2:0] lcdr, lcdg;
 333         wire [1:0] lcdb;
 334
 335         LCDC lcdc(
 336                 .clk(clk),
 337                 .addr(addr[0]),
 338                 .data(data[0]),
 339                 .wr(wr[0]),
 340                 .rd(rd[0]),
 341                 .lcdcirq(lcdcirq),
 342                 .vblankirq(vblankirq),
 343                 .lcdclk(lcdclk),
 344                 .lcdhs(lcdhs),
 345                 .lcdvs(lcdvs),
 346                 .lcdr(lcdr),
 347                 .lcdg(lcdg),
 348                 .lcdb(lcdb));
 349
 350         Framebuffer fb(
 351                 .lcdclk(lcdclk),
 352                 .lcdhs(lcdhs),
 353                 .lcdvs(lcdvs),
 354                 .lcdr(lcdr),
 355                 .lcdg(lcdg),
 356                 .lcdb(lcdb),
 357                 .vgaclk(vgaclk),
 358                 .vgahs(hs),
 359                 .vgavs(vs),
 360                 .vgar(r),
 361                 .vgag(g),
 362                 .vgab(b));
 363
 364         wire [7:0] sleds;
 365 `ifdef isim
 366         assign leds = sleds;
 367 `else
 368         assign leds = sleds | ps2buttons;
 369 `endif
 370         Switches sw(
 371                 .clk(clk),
 372                 .address(addr[0]),
 373                 .data(data[0]),
 374                 .wr(wr[0]),
 375                 .rd(rd[0]),
 376                 .ledout(sleds),
 377                 .switches(switches)
 378                 );
 379
 380 `ifdef isim
 381 `else
 382         PS2Button ps2(
 383                 .clk(clk),
 384                 .inclk(ps2c),
 385                 .indata(ps2d),
 386                 .buttons(ps2buttons)
 387                 );
 388 `endif
 389
 390         Buttons ass(
 391                 .core_clk(clk),
 392                 .addr(addr[0]),
 393                 .data(data[0]),
 394                 .wr(wr[0]),
 395                 .rd(rd[0]),
 396                 .int(btnirq),
 397         `ifdef isim
 398                 .buttons(switches)
 399         `else
 400                 .buttons(ps2buttons)
 401         `endif
 402                 );
 403
 404         AddrMon amon(
 405                 .clk(clk),
 406                 .addr(addr[0]),
 407                 .digit(digits),
 408                 .out(seven),
 409                 .freeze(buttons[0]),
 410                 .periods(
 411                         (state == 2'b00) ? 4'b0010 :
 412                         (state == 2'b01) ? 4'b0001 :
 413                         (state == 2'b10) ? 4'b1000 :
 414                                            4'b0100) );
 415
 416         UART nouart (   /* no u */
 417                 .clk(clk),
 418                 .addr(addr[0]),
 419                 .data(data[0]),
 420                 .wr(wr[0]),
 421                 .rd(rd[0]),
 422                 .serial(serio),
 423                 .serialrx(serin)
 424                 );
 425
 426         InternalRAM ram(
 427                 .clk(clk),
 428                 .address(addr[0]),
 429                 .data(data[0]),
 430                 .wr(wr[0]),
 431                 .rd(rd[0])
 432                 );
 433
 434         MiniRAM mram(
 435                 .clk(clk),
 436                 .address(addr[1]),
 437                 .data(data[1]),
 438                 .wr(wr[1]),
 439                 .rd(rd[1])
 440                 );
 441
 442         Timer tmr(
 443                 .clk(clk),
 444                 .addr(addr[0]),
 445                 .data(data[0]),
 446                 .wr(wr[0]),
 447                 .rd(rd[0]),
 448                 .irq(tmrirq)
 449                 );
 450
 451         Interrupt intr(
 452                 .clk(clk),
 453                 .addr(addr[0]),
 454                 .data(data[0]),
 455                 .wr(wr[0]),
 456                 .rd(rd[0]),
 457                 .vblank(vblankirq),
 458                 .lcdc(lcdcirq),
 459                 .tovf(tmrirq),
 460                 .serial(1'b0),
 461                 .buttons(btnirq),
 462                 .master(irq),
 463                 .ack(ack),
 464                 .jaddr(jaddr));
 465
 466         Soundcore sound(
 467                 .core_clk(clk),
 468                 .addr(addr[0]),
 469                 .data(data[0]),
 470                 .rd(rd[0]),
 471                 .wr(wr[0]),
 472                 .snd_data_l(soundl),
 473                 .snd_data_r(soundr));
 474 endmodule