git.zerfleddert.de Git - fpga-games/blob - galaxian/src/mc_adec.v

   1 //---------------------------------------------------------------------
   2 // FPGA GALAXIAN   ADDRESS DECDER
   3 //
   4 // Version : 2.01
   5 //
   6 // Copyright(c) 2004 Katsumi Degawa , All rights reserved
   7 //
   8 // Important !
   9 //
  10 // This program is freeware for non-commercial use.
  11 // An author does no guarantee about this program.
  12 // You can use this under your own risk.
  13 //
  14 // 2004- 4-30  galaxian modify by K.DEGAWA
  15 // 2004- 5- 6  first release.
  16 // 2004- 8-23  Improvement with T80-IP.
  17 //---------------------------------------------------------------------
  18 //
  19 //GALAXIAN Address Map
  20 //
  21 // Address      Item(R..read-mode W..wight-mode)        Parts
  22 //0000 - 1FFF   CPU-ROM..R                            ( 7H or 7K )
  23 //2000 - 3FFF   CPU-ROM..R                            ( 7L )
  24 //4000 - 47FF   CPU-RAM..RW                           ( 7N  & 7P )
  25 //5000 - 57FF   VID-RAM..RW
  26 //5800 - 5FFF   OBJ-RAM..RW
  27 //6000 -        SW0..R   LAMP......W
  28 //6800 -        SW1..R   SOUND.....W
  29 //7000 -        DIP..R
  30 //7001                   NMI_ON....W
  31 //7004                   STARS_ON..W
  32 //7006                   H_FLIP....W
  33 //7007                   V-FLIP....W
  34 //7800          WDR..R   PITCH.....W
  35 //
  36 //W MODE
  37 //6000 - 6002
  38 //6003                  COIN CNTR
  39 //6004 - 6007           SOUND CONTROL(OSC)
  40 //
  41 //6800                  SOUND CONTROL(FS1)
  42 //6801                  SOUND CONTROL(FS2)
  43 //6802                  SOUND CONTROL(FS3)
  44 //6803                  SOUND CONTROL(HIT)
  45 //6805                  SOUND CONTROL(SHOT)
  46 //6806                  SOUND CONTROL(VOL1)
  47 //6807                  SOUND CONTROL(VOL2)
  48 //
  49
  50 module mc_adec(
  51
  52 I_CLK_12M,
  53 I_CLK_6M,
  54 I_CPU_CLK,
  55 I_RSTn,
  56
  57 I_CPU_A,
  58 I_CPU_D,
  59 I_MREQn,
  60 I_RFSHn,
  61 I_RDn,
  62 I_WRn,
  63 I_H_BL,
  64 I_V_BLn,
  65
  66 O_WAITn,
  67 O_NMIn,
  68 O_CPU_ROM_CSn,
  69 O_CPU_RAM_RDn,
  70 O_CPU_RAM_WRn,
  71 O_CPU_RAM_CSn,
  72 O_OBJ_RAM_RDn,
  73 O_OBJ_RAM_WRn,
  74 O_OBJ_RAM_RQn,
  75 O_VID_RAM_RDn,
  76 O_VID_RAM_WRn,
  77 O_SW0_OEn,
  78 O_SW1_OEn,
  79 O_DIP_OEn,
  80 O_WDR_OEn,
  81 O_LAMP_WEn,
  82 O_SOUND_WEn,
  83 O_PITCHn,
  84 O_H_FLIP,
  85 O_V_FLIP,
  86 O_BD_G,
  87 O_STARS_ON
  88
  89 );
  90
  91
  92 input  I_CLK_12M;
  93 input  I_CLK_6M;
  94 input  I_CPU_CLK;
  95 input  I_RSTn;
  96
  97 input  [15:0]I_CPU_A;
  98 input  I_CPU_D;
  99 input  I_MREQn;
 100 input  I_RFSHn;
 101 input  I_RDn;
 102 input  I_WRn;
 103 input  I_H_BL;
 104 input  I_V_BLn;
 105
 106 output O_WAITn;
 107 output O_NMIn;
 108 output O_CPU_ROM_CSn;
 109 output O_CPU_RAM_RDn;
 110 output O_CPU_RAM_WRn;
 111 output O_CPU_RAM_CSn;
 112 output O_OBJ_RAM_RDn;
 113 output O_OBJ_RAM_WRn;
 114 output O_OBJ_RAM_RQn;
 115 output O_VID_RAM_RDn;
 116 output O_VID_RAM_WRn;
 117 output O_SW0_OEn;
 118 output O_SW1_OEn;
 119 output O_DIP_OEn;
 120 output O_WDR_OEn;
 121 output O_LAMP_WEn;
 122 output O_SOUND_WEn;
 123 output O_PITCHn;
 124 output O_H_FLIP;
 125 output O_V_FLIP;
 126 output O_BD_G;
 127 output O_STARS_ON;
 128
 129
 130 wire   [3:0]W_8E1_Q;
 131 wire   [3:0]W_8E2_Q;
 132 wire   [7:0]W_8P_Q,W_8N_Q,W_8M_Q;
 133 reg    [7:0]W_9N_Q;
 134 wire   W_NMI_ONn = W_9N_Q[1]; //  galaxian
 135 //------  CPU WAITn  ----------------------------------------------
 136
 137 reg    W_6S1_Q,W_6S1_Qn;
 138 reg    W_6S2_Qn;
 139
 140 assign O_WAITn = W_6S1_Qn;
 141 //assign O_WAITn = 1'b1 ; // No Wait
 142
 143 always@(posedge I_CPU_CLK or negedge I_V_BLn)
 144 begin
 145    if(I_V_BLn == 1'b0)begin
 146       W_6S1_Q  <= 1'b0;
 147       W_6S1_Qn <= 1'b1;
 148    end
 149    else begin
 150       W_6S1_Q  <= ~(I_H_BL | W_8P_Q[2]);
 151       W_6S1_Qn <=   I_H_BL | W_8P_Q[2];
 152    end
 153 end
 154
 155 always@(negedge I_CPU_CLK)
 156 begin
 157    W_6S2_Qn <= ~W_6S1_Q;
 158 end
 159 //------  CPU NMIn  -----------------------------------------------
 160 wire  W_V_BL = ~I_V_BLn;
 161 reg   O_NMIn;
 162 always@(posedge W_V_BL or negedge W_NMI_ONn)
 163 begin
 164    if(~W_NMI_ONn)
 165       O_NMIn <= 1'b1;
 166    else
 167       O_NMIn <= 1'b0;
 168 end
 169 //-----------------------------------------------------------------
 170 logic_74xx139 U_8E1(
 171
 172 .I_G(I_MREQn),
 173 .I_Sel(I_CPU_A[15:14]),
 174 .O_Q(W_8E1_Q)
 175
 176 );
 177
 178 //--------   CPU_ROM CS    0000 - 3FFF  ---------------------------
 179 logic_74xx139 U_8E2(
 180
 181 .I_G(I_RDn),
 182 .I_Sel({W_8E1_Q[0],I_CPU_A[13]}),
 183 .O_Q(W_8E2_Q)
 184
 185 );
 186
 187 assign O_CPU_ROM_CSn = W_8E2_Q[0]&W_8E2_Q[1] ;  //   0000 - 3FFF
 188 //-----------------------------------------------------------------
 189 //                  ADDRESS
 190 //    W_8E1_Q[0] = 0000 - 3FFF    ---- CPU_ROM_USE
 191 //    W_8E1_Q[1] = 4000 - 7FFF    ---- GALAXIAN USE   *1
 192 //    W_8E1_Q[2] = 8000 - BFFF    ---- MOONCREST USE
 193 //    W_8E1_Q[3] = C000 - FFFF
 194
 195 logic_74xx138 U_8P(
 196
 197 .I_G1(I_RFSHn),
 198 .I_G2a(W_8E1_Q[1]),   // <= *1
 199 .I_G2b(W_8E1_Q[1]),   // <= *1
 200 .I_Sel(I_CPU_A[13:11]),
 201 .O_Q(W_8P_Q)
 202
 203 );
 204
 205 logic_74xx138 U_8N(
 206
 207 .I_G1(1'b1),
 208 .I_G2a(I_RDn),
 209 .I_G2b(W_8E1_Q[1]),   // <= *1
 210 .I_Sel(I_CPU_A[13:11]),
 211 .O_Q(W_8N_Q)
 212
 213 );
 214
 215 logic_74xx138 U_8M(
 216
 217 //.I_G1(W_6S2_Qn),
 218 .I_G1(1'b1), // No Wait
 219 .I_G2a(I_WRn),
 220 .I_G2b(W_8E1_Q[1]),   // <= *1
 221 .I_Sel(I_CPU_A[13:11]),
 222 .O_Q(W_8M_Q)
 223
 224 );
 225
 226 assign O_BD_G        = ~(W_8E1_Q[0]&W_8P_Q[0]);  //
 227 assign O_OBJ_RAM_RQn = W_8P_Q[3];                //
 228
 229 assign O_CPU_RAM_CSn = W_8N_Q[0]&W_8M_Q[0];      //
 230 assign O_CPU_RAM_RDn = W_8N_Q[0];                //
 231 assign O_CPU_RAM_WRn = W_8M_Q[0];                //
 232 assign O_VID_RAM_RDn = W_8N_Q[2];                //
 233 assign O_OBJ_RAM_RDn = W_8N_Q[3];                //
 234 assign O_SW0_OEn     = W_8N_Q[4];                //
 235 assign O_SW1_OEn     = W_8N_Q[5];                //
 236 assign O_DIP_OEn     = W_8N_Q[6];                //
 237 assign O_WDR_OEn     = W_8N_Q[7];                //
 238
 239 assign O_VID_RAM_WRn = W_8M_Q[2];                //
 240 assign O_OBJ_RAM_WRn = W_8M_Q[3];                //
 241 assign O_LAMP_WEn    = W_8M_Q[4];                //
 242 assign O_SOUND_WEn   = W_8M_Q[5];                //
 243
 244 assign O_PITCHn      = W_8M_Q[7];                //
 245
 246 //---  Parts 9N ---------
 247
 248 always@(posedge I_CLK_12M or negedge I_RSTn)
 249 begin
 250    if(I_RSTn == 1'b0)begin
 251       W_9N_Q <= 0;
 252    end
 253    else begin
 254       if(W_8M_Q[6] == 1'b0)begin
 255          case(I_CPU_A[2:0])
 256             3'h0 : W_9N_Q[0] <= I_CPU_D;
 257             3'h1 : W_9N_Q[1] <= I_CPU_D;
 258             3'h2 : W_9N_Q[2] <= I_CPU_D;
 259             3'h3 : W_9N_Q[3] <= I_CPU_D;
 260             3'h4 : W_9N_Q[4] <= I_CPU_D;
 261             3'h5 : W_9N_Q[5] <= I_CPU_D;
 262             3'h6 : W_9N_Q[6] <= I_CPU_D;
 263             3'h7 : W_9N_Q[7] <= I_CPU_D;
 264          endcase
 265       end
 266    end
 267 end
 268
 269 assign O_STARS_ON    = W_9N_Q[4];                //
 270 assign O_H_FLIP      = W_9N_Q[6];                //
 271 assign O_V_FLIP      = W_9N_Q[7];                //
 272
 273
 274 endmodule