Subversion Repositories srdydrdy_lib

//----------------------------------------------------------------------

// Srdy/Drdy FIFO "B"

//

// The "B" (big) FIFO is design for larger FIFOs

// based around memories, with sizes that may not be a power of 2.

//

// The bound inputs allow multiple FIFO controllers to share a single

// memory.  The enable input is for arbitration between multiple FIFO

// controllers, or between the fifo head and tail controllers on a

// single port memory.

//

// The commit parameter enables write/commit behavior.  This creates

// two write pointers, one which is used for writing to memory and

// a commit pointer which is sent to the tail block.

//

// Naming convention: c = consumer, p = producer, i = internal interface

//----------------------------------------------------------------------

// Author: Guy Hutchison

//

// This block is uncopyrighted and released into the public domain.

//----------------------------------------------------------------------

module sd_fifo_b

  #(parameter width=8,

    parameter depth=256,

    parameter rd_commit=0,

    parameter wr_commit=0,

    parameter asz=$clog2(depth)

    )

    (

     input       clk,

     input       reset,

     input       c_srdy,

     output      c_drdy,

     input       c_commit,

     input       c_abort,

     input [width-1:0] c_data,

     output      p_srdy,

     input       p_drdy,

     input       p_commit,

     input       p_abort,

     output [width-1:0] p_data,

     output [asz:0] usage

     );

  wire [asz-1:0] com_rdptr;              // From tail of sd_fifo_tail_b.v

  wire [asz-1:0] com_wrptr;              // From head of sd_fifo_head_b.v

  wire [asz-1:0] cur_rdptr;              // From tail of sd_fifo_tail_b.v

  wire [asz-1:0] cur_wrptr;              // From head of sd_fifo_head_b.v

  wire [width-1:0]       mem_rd_data;

  wire                  mem_re;                 // From tail of sd_fifo_tail_b.v

  wire                  mem_we;                 // From head of sd_fifo_head_b.v

  wire [asz:0]           usage;                  // From tail of sd_fifo_tail_b.v

  wire [asz-1:0]         bound_high;

  assign bound_high = depth-1;

  sd_fifo_head_b #(depth, wr_commit) head

    (

     // Outputs

     .c_drdy                            (c_drdy),

     .cur_wrptr                         (cur_wrptr[asz-1:0]),

     .com_wrptr                         (com_wrptr[asz-1:0]),

     .mem_we                            (mem_we),

     // Inputs

     .clk                               (clk),

     .reset                             (reset),

     .enable                            (1'b1),

     .c_commit                          (c_commit),

     .c_abort                           (c_abort),

     .c_srdy                            (c_srdy),

     .bound_low                         (0),

     .bound_high                        (bound_high),

     .rdptr                             (com_rdptr));

  behave2p_mem #(width, depth) mem

    (

     // Outputs

     .d_out                             (mem_rd_data),

     // Inputs

     .wr_en                             (mem_we),

     .rd_en                             (mem_re),

     .wr_clk                            (clk),

     .rd_clk                            (clk),

     .d_in                              (c_data),

     .rd_addr                           (cur_rdptr),

     .wr_addr                           (cur_wrptr));

  sd_fifo_tail_b #(width, depth, rd_commit) tail

    (

     // Outputs

     .cur_rdptr                         (cur_rdptr[asz-1:0]),

     .com_rdptr                         (com_rdptr[asz-1:0]),

     .mem_re                            (mem_re),

     .usage                             (usage[asz:0]),

     .p_srdy                            (p_srdy),

     .p_data                            (p_data[width-1:0]),

     // Inputs

     .clk                               (clk),

     .reset                             (reset),

     .enable                            (1'b1),

     .bound_low                         (0),

     .mem_we                            (mem_we),

     .bound_high                        (bound_high),

     .wrptr                             (com_wrptr),

     .p_drdy                            (p_drdy),

     .p_commit                          (p_commit),

     .p_abort                           (p_abort),

     .mem_rd_data                       (mem_rd_data[width-1:0]));

endmodule // sd_fifo_b

// Local Variables:

// verilog-library-directories:("." "../memory" )

// End: