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

   1 //===============================================================================
   2 // FPGA MOONCRESTA VIDEO-LD_PLS_GEN
   3 //
   4 // Version : 2.00
   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- 9-22 The problem which missile didn't sometimes come out from was improved.
  15 //================================================================================
  16
  17
  18 module mc_ld_pls(
  19
  20 I_CLK_6M,
  21 I_H_CNT,
  22 I_3D_DI,
  23
  24 O_LDn,
  25 O_CNTRLDn,
  26 O_CNTRCLRn,
  27 O_COLLn,
  28 O_VPLn,
  29 O_OBJDATALn,
  30 O_MLDn,
  31 O_SLDn
  32
  33 );
  34
  35 input  I_CLK_6M;
  36 input  [8:0]I_H_CNT;
  37 input  I_3D_DI;
  38
  39 output O_LDn;
  40 output O_CNTRLDn;
  41 output O_CNTRCLRn;
  42 output O_COLLn;
  43 output O_VPLn;
  44 output O_OBJDATALn;
  45 output O_MLDn;
  46 output O_SLDn;
  47
  48 reg    W_5C_Q;
  49 always@(posedge I_CLK_6M)
  50    W_5C_Q <= I_H_CNT[0];
  51
  52 //    Parts 4D
  53 wire   W_4D1_G = ~(I_H_CNT[0]&I_H_CNT[1]&I_H_CNT[2]);
  54 wire   [3:0]W_4D1_Q;
  55 wire   [3:0]W_4D2_Q;
  56
  57 logic_74xx139 U_4D1(
  58
  59 .I_G(W_4D1_G),
  60 .I_Sel({I_H_CNT[8],I_H_CNT[3]}),
  61 .O_Q(W_4D1_Q)
  62
  63 );
  64
  65 logic_74xx139 U_4D2(
  66
  67 .I_G(W_5C_Q),
  68 .I_Sel(I_H_CNT[2:1]),
  69 .O_Q(W_4D2_Q)
  70
  71 );
  72
  73 //    Parts 4C
  74 wire   [3:0]W_4C1_Q;
  75 wire   [3:0]W_4C2_Q;
  76
  77 logic_74xx139 U_4C1(
  78
  79 .I_G(W_4D2_Q[1]),
  80 .I_Sel({I_H_CNT[8],I_H_CNT[3]}),
  81 .O_Q(W_4C1_Q)
  82
  83 );
  84
  85 reg    W_4C1_Q3;
  86 always@(negedge I_CLK_6M)    // 2004-9-22 added
  87    W_4C1_Q3 <= W_4C1_Q[3];
  88
  89 reg    W_4C2_B;
  90 always@(posedge W_4C1_Q3)
  91    W_4C2_B <= I_3D_DI;
  92
  93 logic_74xx139 U_4C2(
  94
  95 .I_G(W_4D1_Q[3]),
  96 .I_Sel({W_4C2_B,~(I_H_CNT[6]&I_H_CNT[5]&I_H_CNT[4]&I_H_CNT[3])}),
  97 .O_Q(W_4C2_Q)
  98
  99 );
 100
 101 assign O_LDn       = W_4D1_G;
 102 assign O_CNTRLDn   = W_4D1_Q[2];
 103 assign O_CNTRCLRn  = W_4D1_Q[0];
 104 assign O_COLLn     = W_4D2_Q[2];
 105 assign O_VPLn      = W_4D2_Q[0];
 106 assign O_OBJDATALn = W_4C1_Q[2];
 107 assign O_MLDn      = W_4C2_Q[0];
 108 assign O_SLDn      = W_4C2_Q[1];
 109
 110
 111 endmodule