经典的单时钟FIFO

经典的，可配置的单时钟FIFO实现
 


 


已经经历过流片验证。




module sc_fifo#(

        parameter AW = 5 ,

        parameter DW = 64

    )(

        input clk,rst_n,

        input [ DW-1:0] din,

        input wr,rd,

        output full,empty,

        output reg valid, // data is now valid in dout bus , rd act as ack.

        output  reg  [ DW-1:0] dout

    );




    reg [ AW:0] fifo_cntr  ;

    localparam MAX_FIFO_LEN = (1<= (  MAX_FIFO_LEN   - 2) ;

    assign empty = fifo_cntr == 0 ;

    always @ (posedge clk) valid<=~empty ;

    wire valid_rd =  ( ~empty ) & rd ;

    wire valid_wr =   ( ~full ) & wr ;




    always@(posedge clk) if (~rst_n) wr_ptr <= 0;else if(valid_wr)wr_ptr<=wr_ptr+1;

    always@(posedge clk) if (~rst_n)rd_ptr <= 0 ;else if (valid_rd)rd_ptr <= rd_ptr+1;




    always@(posedge clk)

    casex ({rst_n,valid_wr,valid_rd})

        3'b0xx : fifo_cntr<=0;

        3'b110 : fifo_cntr<=fifo_cntr+1;

        3'b101 : fifo_cntr<=fifo_cntr-1;

        3'b111 ,3'b100 :fifo_cntr<=fifo_cntr ;

    endcase




    always@(posedge clk) if (valid_wr) buff[wr_ptr] <=din ;

    always@(posedge clk)  dout <= buff[rd_ptr] ;




endmodule