module wdt_regfile #
(
    `include        "wdt_params.v"
)
(
    input  wire                              pclk             ,
    input  wire     		                 presetn          ,
    input  wire                              clk_en           ,
    input  wire                              wdt_en_external  ,
    input  wire     		                 wr_en            ,
    input  wire     		                 rd_en            ,
    input  wire        [WDT_ADDR_LHS-2:0]    reg_addr         ,
    input  wire                    [31:0]    ipwdata          ,
    output reg                     [31:0]    iprdata          ,
    input  wire       [WDT_CNT_WIDTH-1:0]    cnt              ,
    input  wire                              wdt_int          ,
    output wire       [WDT_CNT_WIDTH-1:0]    top              ,
    output wire                              restart          ,
    output reg                               wdt_en           ,
    output wire                              eoi_en           ,
    output reg                      [7:0]    rpl              ,
    output wire                              rmod              
);
localparam             WDT_CR_OFFSET     = 0;
localparam             WDT_TORR_OFFSET   = 1;
localparam             WDT_CCVR_OFFSET   = 2;
localparam             WDT_CRR_OFFSET    = 3;
localparam             WDT_STAT_OFFSET   = 4;
localparam             WDT_EOI_OFFSET    = 5;
localparam             WDT_FIXED_TOP_0   = 32'hffff    ;
localparam             WDT_FIXED_TOP_1   = 32'h1ffff   ;
localparam             WDT_FIXED_TOP_2   = 32'h3ffff   ;
localparam             WDT_FIXED_TOP_3   = 32'h7ffff   ;
localparam             WDT_FIXED_TOP_4   = 32'hfffff   ;
localparam             WDT_FIXED_TOP_5   = 32'h1fffff  ;
localparam             WDT_FIXED_TOP_6   = 32'h3fffff  ;
localparam             WDT_FIXED_TOP_7   = 32'h7fffff  ;
localparam             WDT_FIXED_TOP_8   = 32'hffffff  ;
localparam             WDT_FIXED_TOP_9   = 32'h1ffffff ;
localparam             WDT_FIXED_TOP_10  = 32'h3ffffff ;
localparam             WDT_FIXED_TOP_11  = 32'h7ffffff ;
localparam             WDT_FIXED_TOP_12  = 32'hfffffff ;
localparam             WDT_FIXED_TOP_13  = 32'h1fffffff;
localparam             WDT_FIXED_TOP_14  = 32'h3fffffff;
localparam             WDT_FIXED_TOP_15  = 32'h7fffffff;
localparam             WDT_RPL_0         = 1  ;
localparam             WDT_RPL_1         = 3  ;
localparam             WDT_RPL_2         = 7  ;
localparam             WDT_RPL_3         = 15 ;
localparam             WDT_RPL_4         = 31 ;
localparam             WDT_RPL_5         = 63 ;
localparam             WDT_RPL_6         = 127;
localparam             WDT_RPL_7         = 255;
wire                               wdt_cr_en        ;
wire                               wdt_torr_en      ;
wire                               wdt_ccvr_en      ;
wire                               wdt_crr_en       ;
wire                               wdt_stat_en      ;
wire                               wdt_eoi_en       ;
wire                               wdt_cr_we        ;
wire                               wdt_torr_we      ;
wire                               wdt_crr_we       ;
reg                      [ 5:0]    wdt_cr_ir        ;
wire                     [ 5:0]    wdt_cr           ;
reg                      [ 7:0]    wdt_torr_ir      ;
wire                     [ 7:0]    wdt_torr         ;
wire                     [31:0]    wdt_ccvr         ;
wire 		             [ 2:0]    dflt_rpl         ;
wire 			                   dflt_rmod        ;
wire 	                           dflt_wdt_en      ;
wire 		             [ 3:0]    dflt_top_init    ;
wire                     [ 3:0]    dflt_top_bus     ;
wire                     [ 7:0]    int_wdt_torr_ir  ;
reg                      [31:0]    int_cnt          ;
wire                               wdt_eoi_rd       ;
reg                                prev_wdt_eoi_rd  ;
wire                               top_sel          ;
reg         [WDT_CNT_WIDTH-1:0]    int_top          ;
reg         [WDT_CNT_WIDTH-1:0]    int_top_init     ;
reg                                been_started     ;
reg                                been_enabled     ;
assign  wdt_cr_en     = (reg_addr == WDT_CR_OFFSET  ) ? 1'b1 : 1'b0;
assign  wdt_torr_en   = (reg_addr == WDT_TORR_OFFSET) ? 1'b1 : 1'b0;
assign  wdt_ccvr_en   = (reg_addr == WDT_CCVR_OFFSET) ? 1'b1 : 1'b0;
assign  wdt_crr_en    = (reg_addr == WDT_CRR_OFFSET ) ? 1'b1 : 1'b0;
assign  wdt_stat_en   = (reg_addr == WDT_STAT_OFFSET) ? 1'b1 : 1'b0;
assign  wdt_eoi_en    = (reg_addr == WDT_EOI_OFFSET ) ? 1'b1 : 1'b0;
assign  wdt_cr_we   = wdt_cr_en   & wr_en;
assign  wdt_torr_we = wdt_torr_en & wr_en;
assign  wdt_crr_we  = wdt_crr_en  & wr_en;
assign  dflt_rpl    = WDT_DFLT_RPL;
assign  dflt_rmod   = WDT_DFLT_RMOD;
assign  dflt_wdt_en = WDT_ALWAYS_EN;
always @(posedge pclk or negedge presetn)
begin
    if(presetn == 1'b0) 
        wdt_cr_ir <= {1'b0,dflt_rpl, dflt_rmod, dflt_wdt_en};
    else if(wdt_cr_we) begin
   	    wdt_cr_ir[5:1] <= ipwdata[5:1];
   	        wdt_cr_ir[0] <= ipwdata[0];
    end
    else ;
end
assign  wdt_cr[5]   = wdt_cr_ir[5];
assign  wdt_cr[4:2] = wdt_cr_ir[4:2];
assign  wdt_cr[1]   = wdt_cr_ir[1];
assign  wdt_cr[0]   = (WDT_ALWAYS_EN == 1'b0) ? wdt_cr_ir[0]   : WDT_ALWAYS_EN;
always @(posedge pclk or negedge presetn)
begin
    if(presetn == 1'b0) 
        wdt_torr_ir <= WDT_TOP_RST;
    else if(wdt_torr_we)
   	   wdt_torr_ir <= ipwdata[7:0];
    else ;
end
assign  dflt_top_init   = WDT_DFLT_TOP_INIT;
assign  dflt_top_bus    = WDT_DFLT_TOP;
assign  int_wdt_torr_ir = (WDT_ALWAYS_EN == 1'b1 && WDT_DUAL_TOP == 1'b1) ? {dflt_top_init, wdt_torr_ir[3:0]} : wdt_torr_ir;
assign  wdt_torr        = int_wdt_torr_ir; 
assign  restart = (wdt_crr_we) ? (ipwdata[7:0] == 8'b01110110) : 1'b0;
always @ (*) 
begin
    int_cnt = 32'b0;
    int_cnt[WDT_CNT_WIDTH-1:0] = cnt;
end
assign  wdt_ccvr = int_cnt; 
always @(posedge pclk or negedge presetn)
begin
    if(presetn == 1'b0) 
        prev_wdt_eoi_rd <= 1'b0;
    else 
        prev_wdt_eoi_rd <= wdt_eoi_rd;
end
assign  wdt_eoi_rd = wdt_eoi_en & rd_en;
assign  eoi_en = wdt_eoi_rd & ~prev_wdt_eoi_rd;
always @(*) 
begin      
    iprdata = 32'b0;    
    if(wdt_cr_en == 1'b1)
        iprdata[5:0] = wdt_cr;
    else if(wdt_torr_en == 1'b1)
        iprdata[7:0] = wdt_torr;
    else if(wdt_ccvr_en == 1'b1)
        iprdata[WDT_CNT_WIDTH-1:0]  = wdt_ccvr[WDT_CNT_WIDTH-1:0];
    else if(wdt_stat_en == 1'b1)
        iprdata[0]   = wdt_int;     
end
assign  top     = top_sel ? int_top : int_top_init;
assign  top_sel = (WDT_DUAL_TOP == 1'b1) ? been_started : 1'b1;
always @(posedge pclk or negedge presetn)
begin
    if(presetn == 1'b0) 
        been_started <= 1'b0;
    else if(clk_en)
        been_started <= been_enabled;
    else ;
end
always @(posedge pclk or negedge presetn)
begin
    if(presetn == 1'b0) 
        been_enabled <= 1'b0;
    else if(wdt_en)
        been_enabled <= 1'b1;
    else ;
end
always @(*)
begin
    if(WDT_USE_FIX_TOP == 1'b1) begin
        case(wdt_torr[7:4])
            4'd1       : int_top_init = WDT_FIXED_TOP_1;
            4'd2       : int_top_init = WDT_FIXED_TOP_2;
            4'd3       : int_top_init = WDT_FIXED_TOP_3;
            4'd4       : int_top_init = WDT_FIXED_TOP_4;
            4'd5       : int_top_init = WDT_FIXED_TOP_5;
            4'd6       : int_top_init = WDT_FIXED_TOP_6;
            4'd7       : int_top_init = WDT_FIXED_TOP_7;
            4'd8       : int_top_init = WDT_FIXED_TOP_8;
            4'd9       : int_top_init = WDT_FIXED_TOP_9;
            4'd10      : int_top_init = WDT_FIXED_TOP_10;
            4'd11      : int_top_init = WDT_FIXED_TOP_11;
            4'd12      : int_top_init = WDT_FIXED_TOP_12;
            4'd13      : int_top_init = WDT_FIXED_TOP_13;
            4'd14      : int_top_init = WDT_FIXED_TOP_14;
            4'd15      : int_top_init = WDT_FIXED_TOP_15;
            default    : int_top_init = WDT_FIXED_TOP_0;
        endcase
    end
    else begin
        case(wdt_torr[7:4])
            4'd1       : int_top_init = WDT_USER_TOP_INIT_1;
            4'd2       : int_top_init = WDT_USER_TOP_INIT_2;
            4'd3       : int_top_init = WDT_USER_TOP_INIT_3;
            4'd4       : int_top_init = WDT_USER_TOP_INIT_4;
            4'd5       : int_top_init = WDT_USER_TOP_INIT_5;
            4'd6       : int_top_init = WDT_USER_TOP_INIT_6;
            4'd7       : int_top_init = WDT_USER_TOP_INIT_7;
            4'd8       : int_top_init = WDT_USER_TOP_INIT_8;
            4'd9       : int_top_init = WDT_USER_TOP_INIT_9;
            4'd10      : int_top_init = WDT_USER_TOP_INIT_10;
            4'd11      : int_top_init = WDT_USER_TOP_INIT_11;
            4'd12      : int_top_init = WDT_USER_TOP_INIT_12;
            4'd13      : int_top_init = WDT_USER_TOP_INIT_13;
            4'd14      : int_top_init = WDT_USER_TOP_INIT_14;
            4'd15      : int_top_init = WDT_USER_TOP_INIT_15;
            default    : int_top_init = WDT_USER_TOP_INIT_0;
        endcase
    end
end
always @(*)
begin
    if(WDT_USE_FIX_TOP == 1'b1) begin
        case(wdt_torr[3:0])
            4'd1       : int_top = WDT_FIXED_TOP_1;
            4'd2       : int_top = WDT_FIXED_TOP_2;
            4'd3       : int_top = WDT_FIXED_TOP_3;
            4'd4       : int_top = WDT_FIXED_TOP_4;
            4'd5       : int_top = WDT_FIXED_TOP_5;
            4'd6       : int_top = WDT_FIXED_TOP_6;
            4'd7       : int_top = WDT_FIXED_TOP_7;
            4'd8       : int_top = WDT_FIXED_TOP_8;
            4'd9       : int_top = WDT_FIXED_TOP_9;
            4'd10      : int_top = WDT_FIXED_TOP_10;
            4'd11      : int_top = WDT_FIXED_TOP_11;
            4'd12      : int_top = WDT_FIXED_TOP_12;
            4'd13      : int_top = WDT_FIXED_TOP_13;
            4'd14      : int_top = WDT_FIXED_TOP_14;
            4'd15      : int_top = WDT_FIXED_TOP_15;
            default : int_top = WDT_FIXED_TOP_0;
        endcase
    end
    else begin
        case(wdt_torr[3:0])
            4'd1       : int_top = WDT_USER_TOP_1;
            4'd2       : int_top = WDT_USER_TOP_2;
            4'd3       : int_top = WDT_USER_TOP_3;
            4'd4       : int_top = WDT_USER_TOP_4;
            4'd5       : int_top = WDT_USER_TOP_5;
            4'd6       : int_top = WDT_USER_TOP_6;
            4'd7       : int_top = WDT_USER_TOP_7;
            4'd8       : int_top = WDT_USER_TOP_8;
            4'd9       : int_top = WDT_USER_TOP_9;
            4'd10      : int_top = WDT_USER_TOP_10;
            4'd11      : int_top = WDT_USER_TOP_11;
            4'd12      : int_top = WDT_USER_TOP_12;
            4'd13      : int_top = WDT_USER_TOP_13;
            4'd14      : int_top = WDT_USER_TOP_14;
            4'd15      : int_top = WDT_USER_TOP_15;
            default : int_top = WDT_USER_TOP_0;
        endcase
    end
end
always @(*)
begin
    case (wdt_cr[4:2])
        3'd1       : rpl = WDT_RPL_1;
        3'd2       : rpl = WDT_RPL_2;
        3'd3       : rpl = WDT_RPL_3;
        3'd4       : rpl = WDT_RPL_4;
        3'd5       : rpl = WDT_RPL_5;
        3'd6       : rpl = WDT_RPL_6;
        3'd7       : rpl = WDT_RPL_7;
        default    : rpl = WDT_RPL_0;
    endcase
end
always @(posedge pclk or negedge presetn)
begin
    if(presetn == 1'b0)
        wdt_en <= 1'b0;
    else if(wdt_cr[0] == 1'b1)
        wdt_en <= 1'b1;
    else if(wdt_en_external == 1'b1)
        wdt_en <= 1'b1;
    else
        wdt_en <= 1'b0;
end
assign  rmod   = wdt_cr[1];
endmodule 