[fpga-games] / galaxian / src / mc_video.v

//===============================================================================
// FPGA GALAXIAN  VIDEO
//
// Version : 2.50
//
// Copyright(c) 2004 Katsumi Degawa , All rights reserved
//
// Important !
//
// This program is freeware for non-commercial use. 
// An author does no guarantee about this program.
// You can use this under your own risk.
//
// 2004- 4-30  galaxian modify by K.DEGAWA
// 2004- 5- 6  first release.
// 2004- 8-23  Improvement with T80-IP.
// 2004- 9-22  The problem which missile didn't sometimes come out from was improved.
//================================================================================
//-----------------------------------------------------------------------------------------
// H_CNT[0],H_CNT[1],H_CNT[2],H_CNT[3],H_CNT[4],H_CNT[5],H_CNT[6],H_CNT[7],H_CNT[8],  
//    1 H     2 H      4H       8H       16 H     32H      64 H     128 H   256 H
//-----------------------------------------------------------------------------------------
// V_CNT[0], V_CNT[1], V_CNT[2], V_CNT[3], V_CNT[4], V_CNT[5], V_CNT[6], V_CNT[7]  
//    1 V      2 V       4 V       8 V       16 V      32 V      64 V     128 V 
//-----------------------------------------------------------------------------------------

module mc_video(

I_CLK_18M,
I_CLK_12M,
I_CLK_6M,
I_H_CNT,
I_V_CNT,
I_H_FLIP,
I_V_FLIP,
I_V_BLn,
I_C_BLn,

I_A,
I_OBJ_SUB_A,
I_BD,
I_OBJ_RAM_RQn,
I_OBJ_RAM_RDn,
I_OBJ_RAM_WRn,
I_VID_RAM_RDn,
I_VID_RAM_WRn,

O_OBJ_ROM_A,
I_OBJ_ROM_A_D,
I_OBJ_ROM_B_D,

O_C_BLnX,
O_8HF,
O_256HnX,
O_1VF,
O_MISSILEn,
O_SHELLn,
O_BD,
O_VID,
O_COL

);

input  I_CLK_18M;
input  I_CLK_12M;
input  I_CLK_6M;
input  [8:0]I_H_CNT;
input  [7:0]I_V_CNT;
input  I_H_FLIP;
input  I_V_FLIP;
input  I_V_BLn;
input  I_C_BLn;

input  [9:0]I_A;
input  [7:0]I_BD;
input  [2:0]I_OBJ_SUB_A;
input  I_OBJ_RAM_RQn;
input  I_OBJ_RAM_RDn;
input  I_OBJ_RAM_WRn;
input  I_VID_RAM_RDn;
input  I_VID_RAM_WRn;

output [10:0]O_OBJ_ROM_A;
input  [7:0]I_OBJ_ROM_A_D;
input  [7:0]I_OBJ_ROM_B_D;

output O_C_BLnX;
output O_8HF;
output O_256HnX;
output O_1VF;
output O_MISSILEn;
output O_SHELLn;

output [7:0]O_BD;
output [1:0]O_VID;
output [2:0]O_COL;

wire   WB_LDn;
wire   WB_CNTRLDn;
wire   WB_CNTRCLRn;
wire   WB_COLLn;
wire   WB_VPLn;
wire   WB_OBJDATALn;
wire   WB_MLDn;
wire   WB_SLDn;
wire   W_3D;
reg    W_LDn;
reg    W_CNTRLDn;
reg    W_CNTRCLRn;
reg    W_COLLn;
reg    W_VPLn;
reg    W_OBJDATALn;
reg    W_MLDn;
reg    W_SLDn;

always@(negedge I_CLK_12M)
begin
   W_LDn <= WB_LDn;
   W_CNTRLDn <= WB_CNTRLDn;
   W_CNTRCLRn <= WB_CNTRCLRn;
   W_COLLn <= WB_COLLn;
   W_VPLn <= WB_VPLn;
   W_OBJDATALn <= WB_OBJDATALn;
   W_MLDn <= WB_MLDn;
   W_SLDn <= WB_SLDn;
end

mc_ld_pls LD_PLS(

.I_CLK_6M(~I_CLK_6M),
.I_H_CNT(I_H_CNT),
.I_3D_DI(W_3D),

.O_LDn(WB_LDn),
.O_CNTRLDn(WB_CNTRLDn),
.O_CNTRCLRn(WB_CNTRCLRn),
.O_COLLn(WB_COLLn),
.O_VPLn(WB_VPLn),
.O_OBJDATALn(WB_OBJDATALn),
.O_MLDn(WB_MLDn),
.O_SLDn(WB_SLDn)

);

wire   W_H_FLIP1 = ~I_H_CNT[8]&I_H_FLIP;

wire   [7:3]W_HF_CNT = I_H_CNT[7:3]^{5{W_H_FLIP1}};
wire   [7:0]W_VF_CNT = I_V_CNT[7:0]^{8{I_V_FLIP}};

assign O_8HF = W_HF_CNT[3];
assign O_1VF = I_V_CNT[0]^1'b1; //XXX: breaks when flipped

reg    [7:0]W_OBJ_D;
wire   [3:0]W_6J_DA = {I_H_FLIP  ,           W_HF_CNT[7],W_HF_CNT[3],I_H_CNT[2]};
wire   [3:0]W_6J_DB = {W_OBJ_D[6],W_HF_CNT[3]&I_H_CNT[1], I_H_CNT[2],I_H_CNT[1]};
wire   [3:0]W_6J_Q  = I_H_CNT[8] ? W_6J_DB:W_6J_DA;

wire   W_H_FLIP2 = W_6J_Q[3];
//   Prats  4F,5F
wire   [7:0]W_OBJ_RAM_AB = {1'b0,I_H_CNT[8],W_6J_Q[2],W_HF_CNT[6:4],W_6J_Q[1:0]};
wire   [7:0]W_OBJ_RAM_A  = I_OBJ_RAM_RQn ? W_OBJ_RAM_AB: I_A[7:0] ;

wire   [7:0]W_OBJ_RAM_DOA,W_OBJ_RAM_DOB;

reg    [7:0]W_H_POSI;
always@(posedge I_CLK_12M) W_H_POSI <= W_OBJ_RAM_DOB;

mc_obj_ram OBJ_RAM(

.I_CLKA(I_CLK_12M),
.I_ADDRA(I_A[7:0]),
.I_WEA(~I_OBJ_RAM_WRn),
.I_CEA(~I_OBJ_RAM_RQn),
.I_DA(I_BD),
.O_DA(W_OBJ_RAM_DOA),

.I_CLKB(I_CLK_12M),
.I_ADDRB(W_OBJ_RAM_AB),
.I_WEB(1'b0),
.I_CEB(1'b1),
.I_DB(8'h00),
.O_DB(W_OBJ_RAM_DOB)

);

wire   [7:0]W_OBJ_RAM_D = I_OBJ_RAM_RDn ?  8'h00: W_OBJ_RAM_DOA;
//   Prats  4L
always@(posedge W_OBJDATALn) W_OBJ_D <= W_H_POSI; 
//   Prats  4,5N

wire   [8:0]W_45N_Q = W_VF_CNT[7:0] + W_H_POSI ;
assign W_3D = ~(&W_45N_Q[7:0]); 

reg    [7:0]W_2M_Q;
always@(posedge W_VPLn or negedge I_V_BLn)
begin
   if(I_V_BLn==1'b0)
      W_2M_Q <= 0;
   else
      W_2M_Q <= W_45N_Q[7:0];
end

wire   W_2N = I_H_CNT[8]&W_OBJ_D[7];
wire   [3:0]W_1M = W_2M_Q[3:0]^{W_2N,W_2N,W_2N,W_2N};

wire   W_VID_RAM_CSn = I_VID_RAM_RDn & I_VID_RAM_WRn;

wire   [7:0]W_VID_RAM_DI = I_VID_RAM_WRn ? 8'h00 : I_BD ;
wire   [7:0]W_VID_RAM_DOA;

wire   [11:0]W_VID_RAM_AA = {~(&W_2M_Q[7:4]),W_VID_RAM_CSn,              10'h00 /*I_A[9:0]*/};
wire   [11:0]W_VID_RAM_AB = {           1'b0,         1'b0,W_2M_Q[7:4],W_1M[3],W_HF_CNT[7:3]};

wire   [11:0]W_VID_RAM_A  = I_C_BLn ? W_VID_RAM_AB:W_VID_RAM_AA;

wire   [7:0]W_VID_RAM_D = I_VID_RAM_RDn ? 8'h00 :W_VID_RAM_DOA;

wire   [7:0]W_VID_RAM_DOB;

mc_vid_ram VID_RAM(

.I_CLKA(I_CLK_12M),
.I_ADDRA(I_A[9:0]),
.I_DA(W_VID_RAM_DI),
.I_WEA(~I_VID_RAM_WRn),
.I_CEA(~W_VID_RAM_CSn),
.O_DA(W_VID_RAM_DOA),

.I_CLKB(I_CLK_12M),
.I_ADDRB(W_VID_RAM_A[9:0]),
.I_DB(8'h00),
.I_WEB(1'b0),
.I_CEB(1'b1),
.O_DB(W_VID_RAM_DOB)

);
//--  VIDEO DATA OUTPUT  --------------
assign O_BD = W_OBJ_RAM_D | W_VID_RAM_D;

wire   W_SRLD = ~(W_LDn | W_VID_RAM_A[11]);

wire   [7:0]W_OBJ_ROM_AB = {W_OBJ_D[5:0],W_1M[3],W_OBJ_D[6]^I_H_CNT[3]};

wire   [7:0]W_OBJ_ROM_A = I_H_CNT[8] ? W_OBJ_ROM_AB: W_VID_RAM_DOB;

assign O_OBJ_ROM_A = {W_OBJ_ROM_A,W_1M[2:0]};

wire   [7:0]W_1K_D = I_OBJ_ROM_A_D;
wire   [7:0]W_1H_D = I_OBJ_ROM_B_D;

//---------------------------------------------------------------------------------
wire   W_2L_Qa,W_2K_Qd;
wire   W_2J_Qa,W_2H_Qd;
wire   W_H_FLIP2X;

wire   [3:0]W_3L_A = {W_2J_Qa,W_2L_Qa,  1'b1,W_SRLD};
wire   [3:0]W_3L_B = {W_2H_Qd,W_2K_Qd,W_SRLD,  1'b1};  
wire   [3:0]W_3L_Y = W_H_FLIP2X ? W_3L_B: W_3L_A;   //  [3]=RAW1,[2]=RAW0

wire   W_RAW0 = W_3L_Y[2];
wire   W_RAW1 = W_3L_Y[3];

wire   W_SRCLK = I_CLK_6M;
//------  PARTS 2KL  ---------------------------------------------- 
wire   [1:0]C_2KL = W_3L_Y[1:0];
wire   [7:0]I_2KL = W_1K_D;
reg    [7:0]reg_2KL;

assign W_2L_Qa = reg_2KL[7];
assign W_2K_Qd = reg_2KL[0];
always@(posedge W_SRCLK)
begin
   case(C_2KL)
      2'b00: reg_2KL <= reg_2KL;
      2'b10: reg_2KL <= {reg_2KL[6:0],1'b0};
      2'b01: reg_2KL <= {1'b0,reg_2KL[7:1]};
      2'b11: reg_2KL <= I_2KL;
   endcase
end
//------  PARTS 2HJ  ---------------------------------------------- 
wire   [1:0]C_2HJ = W_3L_Y[1:0];
wire   [7:0]I_2HJ = W_1H_D;
reg    [7:0]reg_2HJ;

assign W_2J_Qa = reg_2HJ[7];
assign W_2H_Qd = reg_2HJ[0];
always@(posedge W_SRCLK)
begin
   case(C_2HJ)
      2'b00: reg_2HJ <= reg_2HJ;
      2'b10: reg_2HJ <= {reg_2HJ[6:0],1'b0};
      2'b01: reg_2HJ <= {1'b0,reg_2HJ[7:1]};
      2'b11: reg_2HJ <= I_2HJ;
   endcase
end

//-----  SHT2 -----------------------------------------------------
//  Prats 6K
reg    [2:0]W_6K_Q;
always@(posedge W_COLLn) W_6K_Q <= W_H_POSI[2:0];

//  Prats 6P
reg    [6:0]W_6P_Q;
always@(posedge I_CLK_6M)
begin
   if(W_LDn==1'b0) W_6P_Q <= {W_H_FLIP2,W_H_FLIP1,I_C_BLn,~I_H_CNT[8],W_6K_Q[2:0]};
   else            W_6P_Q <= W_6P_Q;
end

assign W_H_FLIP2X = W_6P_Q[6];
wire   W_H_FLIP1X = W_6P_Q[5];
wire   W_C_BLnX   = W_6P_Q[4];
wire   W_256HnX   = W_6P_Q[3];
wire   [2:0]W_CD  = W_6P_Q[2:0];

assign O_256HnX   = W_256HnX;
assign O_C_BLnX   = W_C_BLnX;

wire   W_45T_CLR = W_CNTRCLRn | W_256HnX ;
reg    [7:0]W_45T_Q;

always@(posedge I_CLK_6M)
begin
   if(W_45T_CLR==1'b0)
      W_45T_Q <= 0;
   else if(W_CNTRLDn==1'b0)
      W_45T_Q <= W_H_POSI;
   else
      W_45T_Q <= W_45T_Q + 1;
end

wire   [7:0]W_LRAM_A = W_45T_Q^{8{W_H_FLIP1X}};
wire   W_LRAM_WE = ~I_CLK_6M;

wire   [4:0]W_LRAM_DI;
wire   [4:0]W_LRAM_DO;

reg    [1:0]W_RV;
reg    [2:0]W_RC;
wire   W_1U_CLK = ~I_CLK_6M;

always@(posedge W_1U_CLK)
begin
      W_RV <= W_LRAM_DO[1:0];    
      W_RC <= W_LRAM_DO[4:2];
end

wire   W_LRAM_AND = ~(~((W_LRAM_A[4]|W_LRAM_A[5])|(W_LRAM_A[6]|W_LRAM_A[7]))|W_256HnX );
wire   W_RAW_OR = W_RAW0 | W_RAW1 ;

wire   [1:0]W_VID;
wire   [2:0]W_COL;

assign W_VID[0] = ~(~(W_RAW0&W_RV[1])&W_RV[0]);
assign W_VID[1] = ~(~(W_RAW1&W_RV[0])&W_RV[1]);
assign W_COL[0] = ~(~(W_RAW_OR&W_CD[0]&W_RC[1]&W_RC[2])&W_RC[0]);
assign W_COL[1] = ~(~(W_RAW_OR&W_CD[1]&W_RC[2]&W_RC[0])&W_RC[1]);
assign W_COL[2] = ~(~(W_RAW_OR&W_CD[2]&W_RC[0]&W_RC[1])&W_RC[2]);

assign O_VID = W_VID;
assign O_COL = W_COL;

assign W_LRAM_DI[0] = W_LRAM_AND&W_VID[0];
assign W_LRAM_DI[1] = W_LRAM_AND&W_VID[1]; 
assign W_LRAM_DI[2] = W_LRAM_AND&W_COL[0];
assign W_LRAM_DI[3] = W_LRAM_AND&W_COL[1];
assign W_LRAM_DI[4] = W_LRAM_AND&W_COL[2];

mc_lram LRAM(

.I_CLK(I_CLK_18M),
.I_ADDR(W_LRAM_A),
.I_WE(W_LRAM_WE),
.I_D(W_LRAM_DI),
.O_Dn(W_LRAM_DO)

);

mc_missile MISSILE(

.I_CLK_18M(I_CLK_18M),
.I_CLK_6M(I_CLK_6M),
.I_C_BLn_X(W_C_BLnX),
.I_MLDn(W_MLDn),
.I_SLDn(W_SLDn),
.I_HPOS(W_H_POSI),

.O_MISSILEn(O_MISSILEn),
.O_SHELLn(O_SHELLn)

);

endmodule