Saw typo on line 57.
On Sun, Jun 05, 2005 at 10:47:49PM -0400, Timothy Miller wrote:
> // Basic fifo
> // Copyright 2005, Timothy Miller
> // LGPL license
>
>
> module basic_fifo(
> clock,
> reset,
>
> data_in,
> enq,
> full,
>
> data_out,
> valid_out,
> deq
> );
>
> parameter fifo_width = 32;
> // fifo depth is hard-wired to 16
>
> input clock, reset;
>
> input [fifo_width-1:0] data_in;
> input enq;
> output full;
> reg full;
>
> output [fifo_width-1:0] data_out;
> reg [fifo_width-1:0] data_out;
> output valid_out;
> reg valid_out;
> input deq;
>
>
>
> reg [fifo_width-1:0] fifo_data [0:15];
> reg [4:0] fifo_head, fifo_tail;
> reg [4:0] next_tail;
>
>
> // accept input
> wire next_full = fifo_head[3:0] == next_tail[3:0] &&
> fifo_head[4] != next_tail[4];
> wire is_full = fifo_head[3:0] == fifo_tail[3:0] &&
> fifo_head[4] != fifo_tail[4];
> always @(posedge clock) begin
> if (reset) begin
> fifo_tail <= 0;
> next_tail <= 1;
> full <= 0;
> end else begin
> if (!full && enq) begin
> // We can only enqueue when not full
> fifo_data[fifo_tail[3:0]] <= data_in;
> next_tail <= next_tail + 1;
> fifo_tall <= next_tail;
^
>
> // We have to compute if it's full on next cycle
> full <= next_full;
> end else begin
> full <= is_full;
> end
> end
> end
>
>
> // provide output
> wire is_empty = fifo_head == fifo_tail;
> always @(posedge clock) begin
> if (reset) begin
> valid_out <= 0;
> data_out <= 0;
> fifo_head <= 0;
> end else begin
> // If no valid out or we're dequeueing, we want to grab
> // the next data. If we're empty, we don't get valid_out,
> // so we don't care if it's garbage.
> if (!valid_out || deq) begin
> data_out <= fifo_data[fifo_head[3:0]];
> end
>
> if (!is_empty) begin
> if (!valid_out || deq) begin
> fifo_head <= fifo_head + 1;
> end
> valid_out <= 1;
> end else begin
> if (deq) valid_out <= 0;
> end
> end
> end
>
>
> endmodule
>
> _______________________________________________
> Open-graphics mailing list
> [email protected]
> http://lists.duskglow.com/mailman/listinfo/open-graphics
> List service provided by Duskglow Consulting, LLC (www.duskglow.com)
_______________________________________________
Open-graphics mailing list
[email protected]
http://lists.duskglow.com/mailman/listinfo/open-graphics
List service provided by Duskglow Consulting, LLC (www.duskglow.com)
