module LCD_CTRL(clk,reset,datain,cmd,cmd_valid,dataout,output_valid,busy);

input clk;
input reset;
input [7:0] datain;
input [2:0] cmd;
input cmd_valid;
output [7:0] dataout;
output output_valid;
output busy;


parameter [0:0] //synopsys enum state_info
  RST = 1'b0,
  CMD_MODE = 1'b1;
reg current_state,
    next_state;
reg output_valid,
    busy;
reg magnifi,
    zoomout;
reg [2:0] x_addr,
          y_addr,
          cmd_use;
reg [6:0] pc;
reg [7:0] dataout;
reg [7:0] image_buf[0:63];
reg [7:0] output_buf[0:15];

integer i;

always@(posedge clk or posedge reset)
begin
  if(reset==1'b1)
  begin
    current_state <= RST;
  end
  else
  begin
    current_state <= next_state;
  end
end

always@(reset or current_state or cmd_valid)
begin
  case(current_state)
    RST:
    begin
      if(cmd_valid == 1'b0)
        next_state = current_state;
      else
        next_state = CMD_MODE;
    end
    CMD_MODE:next_state = current_state;
  endcase
end

always@(posedge clk)
begin
  case(current_state)
    RST:
    begin
      x_addr <= 3'b0;
      y_addr <= 3'b0;
      pc <= 7'h01;
      busy <= 1'b0;
      cmd_use <= cmd;
      zoomout <= 1'b0;
      dataout <= 8'h0;
      magnifi <= 1'b0;
      for(i=0;i<64;i=i+1)
        image_buf[i] <= 8'b0;
      for(i=0;i<16;i=i+1)
        output_buf[i]<= 8'b0;
    end
    CMD_MODE:
    begin
      if(cmd_valid == 1'b1)
      begin
        if(zoomout == 1'b1 && cmd[2] == 1'b1)
          cmd_use <= 3'b011;
        else if(cmd_use == 3'b011 && cmd[2]==1'b1)
          cmd_use <= 3'b011;
        else
          cmd_use <= cmd;
      end
      else
        cmd_use <= cmd_use;
          if(cmd_use == 3'b011 && cmd[2:1] != 2'b01)
            zoomout <= 1'b1;
          else if(cmd_use == 3'b010)
            zoomout <= 1'b0;
          else
            zoomout <= zoomout;
          if(cmd_use == 3'b001)
          begin
            case(pc)
              7'h42:dataout <= output_buf[0];
              7'h43:dataout <= output_buf[1];
              7'h44:dataout <= output_buf[2];
              7'h45:dataout <= output_buf[3];
              7'h46:dataout <= output_buf[4];
              7'h47:dataout <= output_buf[5];
              7'h48:dataout <= output_buf[6];
              7'h49:dataout <= output_buf[7];
              7'h4a:dataout <= output_buf[8];
              7'h4b:dataout <= output_buf[9];
              7'h4c:dataout <= output_buf[10];
              7'h4d:dataout <= output_buf[11];
              7'h4e:dataout <= output_buf[12];
              7'h4f:dataout <= output_buf[13];
              7'h50:dataout <= output_buf[14];
              7'h51:dataout <= output_buf[15];
              default:dataout<= dataout;
            endcase
          end
          else
          begin
            case(pc)
              7'h03:dataout <= output_buf[0];
              7'h04:dataout <= output_buf[1];
              7'h05:dataout <= output_buf[2];
              7'h06:dataout <= output_buf[3];
              7'h07:dataout <= output_buf[4];
              7'h08:dataout <= output_buf[5];
              7'h09:dataout <= output_buf[6];
              7'h0a:dataout <= output_buf[7];
              7'h0b:dataout <= output_buf[8];
              7'h0c:dataout <= output_buf[9];
              7'h0d:dataout <= output_buf[10];
              7'h0e:dataout <= output_buf[11];
              7'h0f:dataout <= output_buf[12];
              7'h10:dataout <= output_buf[13];
              7'h11:dataout <= output_buf[14];
              7'h12:dataout <= output_buf[15];
              default:dataout<= dataout;
            endcase
          end
          if((cmd_use == 3'b001) && pc <= 7'h51) //LOADDATA
          begin
            if(pc == 7'h51)
            begin
              pc <= 7'b0;
              busy<= 1'b0;
            end
            else
            begin
              pc <= pc + 1'b1;
              busy <= 1'b1;
            end
            if(pc >= 7'h42)
              output_valid <= 1'b1;
            else
              output_valid <= 1'b0;
            x_addr <= x_addr;
            y_addr <= y_addr;
            magnifi <= 1'b0;
            if(pc <= 7'h40 && pc >=7'h01 )
            begin
              image_buf[63] <= datain;
              for(i=62;i>=0;i=i-1)
                image_buf[i] <= image_buf[i+1];
            end
            else
              for(i=0;i<64;i=i+1)
                image_buf[i] <= image_buf[i];
            if(pc >7'h3f)
            begin
              output_buf[0] <= image_buf[0] ;
              output_buf[1] <= image_buf[2] ;
              output_buf[2] <= image_buf[4] ;
              output_buf[3] <= image_buf[6] ;
              output_buf[4] <= image_buf[16];
              output_buf[5] <= image_buf[18];
              output_buf[6] <= image_buf[20];
              output_buf[7] <= image_buf[22];
              output_buf[8] <= image_buf[32];
              output_buf[9] <= image_buf[34];
              output_buf[10]<= image_buf[36];
              output_buf[11]<= image_buf[38];
              output_buf[12]<= image_buf[48];
              output_buf[13]<= image_buf[50];
              output_buf[14]<= image_buf[52];
              output_buf[15]<= image_buf[54];
            end
            else
            begin
              for(i=0;i<16;i=i+1)
                output_buf[i]<=output_buf[i];
            end
          end
          else
          begin
            for(i=0;i<64;i=i+1)
              image_buf[i]<=image_buf[i];
            if((cmd_use == 3'b000) && pc <= 7'h12) //ReFlash
            begin
              if(pc == 7'h12)
              begin
                pc <= 7'b0;
                busy <= 1'b0;
              end
              else
              begin
                pc <= pc + 1'b1;
                busy <= 1'b1;
              end
              if(pc >= 7'h03)
                output_valid <= 1'b1;
              else
                output_valid <= 1'b0;
              x_addr <= x_addr;
              y_addr <= y_addr;
              magnifi <= magnifi;
              for(i=0;i<16;i=i+1)
                output_buf[i]<=output_buf[i];
            end
            else if((cmd_use[2:1] == 2'b01) && (pc <= 7'h12)) //ZOOM IN / ZOOM OUT
            begin
              if(pc == 7'h12)
              begin
                busy <= 1'b0;
                pc <= 7'b0;
              end
              else
              begin
                busy <= 1'b1;
                pc <= pc + 1'b1;
              end
              if( pc >= 7'h03)
                output_valid <= 1'b1;
              else
                output_valid <= 1'b0;
              magnifi <= ~cmd_use[0];
              if(magnifi == 1'b0)
              begin
                x_addr <= 3'b0;
                y_addr <= 3'b0;
                output_buf[0] <= image_buf[0] ;
                output_buf[1] <= image_buf[2] ;
                output_buf[2] <= image_buf[4] ;
                output_buf[3] <= image_buf[6] ;
                output_buf[4] <= image_buf[16];
                output_buf[5] <= image_buf[18];
                output_buf[6] <= image_buf[20];
                output_buf[7] <= image_buf[22];
                output_buf[8] <= image_buf[32];
                output_buf[9] <= image_buf[34];
                output_buf[10]<= image_buf[36];
                output_buf[11]<= image_buf[38];
                output_buf[12]<= image_buf[48];
                output_buf[13]<= image_buf[50];
                output_buf[14]<= image_buf[52];
                output_buf[15]<= image_buf[54];
              end
              else
              begin
                x_addr <= 3'b010;
                y_addr <= 3'b010;
                output_buf[0] <= image_buf[18];
                output_buf[1] <= image_buf[19];
                output_buf[2] <= image_buf[20];
                output_buf[3] <= image_buf[21];
                output_buf[4] <= image_buf[26];
                output_buf[5] <= image_buf[27];
                output_buf[6] <= image_buf[28];
                output_buf[7] <= image_buf[29];
                output_buf[8] <= image_buf[34];
                output_buf[9] <= image_buf[35];
                output_buf[10]<= image_buf[36];
                output_buf[11]<= image_buf[37];
                output_buf[12]<= image_buf[42];
                output_buf[13]<= image_buf[43];
                output_buf[14]<= image_buf[44];
                output_buf[15]<= image_buf[45];
              end
            end
            else //SHIRFT
            begin
              if(pc == 7'h12)
              begin
                busy <= 1'b0;
                pc <= 7'b0;
              end
              else
              begin
                busy <= 1'b1;
                pc <= pc + 1'b1;
              end
              if(pc >= 7'h03)
                output_valid <= 1'b1;
              else
                output_valid <= 1'b0;
              magnifi <= magnifi;
              if(pc == 7'h1 )
              begin
                if(cmd_use[1:0] == 2'b00)
                begin
                  if(x_addr == 3'b100)
                    x_addr <= x_addr;
                  else
                    x_addr <= x_addr + 1'b1;
                  y_addr <= y_addr;
                end
                else if(cmd_use[1:0] == 2'b01)
                begin
                  if(x_addr == 2'b00)
                    x_addr <= x_addr;
                  else
                    x_addr <= x_addr - 1'b1;
                  y_addr <= y_addr;
                end
                else if(cmd_use[1:0] == 2'b10)
                begin
                  if(y_addr == 2'b00)
                    y_addr <= y_addr;
                  else
                    y_addr <= y_addr - 1'b1;
                  x_addr <= x_addr;
                end
                else
                begin
                  if(y_addr == 3'b100)
                    y_addr <= y_addr;
                  else
                    y_addr <= y_addr + 1'b1;
                  x_addr <= x_addr;
                end
              end
              else
              begin
                x_addr <= x_addr;
                y_addr <= y_addr;
              end
              output_buf[0] <= image_buf[8*y_addr+x_addr];
              output_buf[1] <= image_buf[8*y_addr+x_addr+1];
              output_buf[2] <= image_buf[8*y_addr+x_addr+2];
              output_buf[3] <= image_buf[8*y_addr+x_addr+3];
              output_buf[4] <= image_buf[8*(y_addr+1)+x_addr];
              output_buf[5] <= image_buf[8*(y_addr+1)+x_addr+1];
              output_buf[6] <= image_buf[8*(y_addr+1)+x_addr+2];
              output_buf[7] <= image_buf[8*(y_addr+1)+x_addr+3];
              output_buf[8] <= image_buf[8*(y_addr+2)+x_addr];
              output_buf[9] <= image_buf[8*(y_addr+2)+x_addr+1];
              output_buf[10]<= image_buf[8*(y_addr+2)+x_addr+2];
              output_buf[11]<= image_buf[8*(y_addr+2)+x_addr+3];
              output_buf[12]<= image_buf[8*(y_addr+3)+x_addr];
              output_buf[13]<= image_buf[8*(y_addr+3)+x_addr+1];
              output_buf[14]<= image_buf[8*(y_addr+3)+x_addr+2];
              output_buf[15]<= image_buf[8*(y_addr+3)+x_addr+3];
            end
          end
        end
      endcase
    end

endmodule