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authorMatt Ettus <matt@ettus.com>2009-09-04 16:33:00 -0700
committerMatt Ettus <matt@ettus.com>2009-09-04 16:33:00 -0700
commit1d26231a1a541eb4015f38409a85ce97a4e98bd7 (patch)
treed5b50b7de4a3453c6761c37886fdc4ddc30ee06a /control_lib
parentf6548b5f7b6724e822ad3a6af32dc0910332f13d (diff)
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no longer used, replaced by newfifo version
Diffstat (limited to 'control_lib')
-rw-r--r--control_lib/fifo_2clock.v66
1 files changed, 0 insertions, 66 deletions
diff --git a/control_lib/fifo_2clock.v b/control_lib/fifo_2clock.v
deleted file mode 100644
index 6b1eb607e..000000000
--- a/control_lib/fifo_2clock.v
+++ /dev/null
@@ -1,66 +0,0 @@
-
-module fifo_2clock
- #(parameter DWIDTH=32, AWIDTH=9)
- (input wclk, input [DWIDTH-1:0] datain, input write, output full, output reg [AWIDTH-1:0] level_wclk,
- input rclk, output [DWIDTH-1:0] dataout, input read, output empty, output reg [AWIDTH-1:0] level_rclk,
- input arst);
-
- reg [AWIDTH-1:0] wr_addr, rd_addr;
- wire [AWIDTH-1:0] wr_addr_rclk, rd_addr_wclk;
- wire [AWIDTH-1:0] next_rd_addr;
- wire enb_read;
-
- // Write side management
- wire [AWIDTH-1:0] next_wr_addr = wr_addr + 1;
- always @(posedge wclk or posedge arst)
- if(arst)
- wr_addr <= 0;
- else if(write)
- wr_addr <= next_wr_addr;
- assign full = (next_wr_addr == rd_addr_wclk);
-
- // RAM for data storage. Data out is registered, complicating the
- // read side logic
- ram_2port #(.DWIDTH(DWIDTH),.AWIDTH(AWIDTH)) mac_rx_ff_ram
- (.clka(wclk),.ena(1'b1),.wea(write),.addra(wr_addr),.dia(datain),.doa(),
- .clkb(rclk),.enb(enb_read),.web(1'b0),.addrb(next_rd_addr),.dib(0),.dob(dataout) );
-
- // Read side management
- reg data_valid;
- assign empty = ~data_valid;
- assign next_rd_addr = rd_addr + data_valid;
- assign enb_read = read | ~data_valid;
-
- always @(posedge rclk or posedge arst)
- if(arst)
- rd_addr <= 0;
- else if(read)
- rd_addr <= rd_addr + 1;
-
- always @(posedge rclk or posedge arst)
- if(arst)
- data_valid <= 0;
- else
- if(read & (next_rd_addr == wr_addr_rclk))
- data_valid <= 0;
- else if(next_rd_addr != wr_addr_rclk)
- data_valid <= 1;
-
- // Send pointers across clock domains via gray code
- gray_send #(.WIDTH(AWIDTH)) send_wr_addr
- (.clk_in(wclk),.addr_in(wr_addr),
- .clk_out(rclk),.addr_out(wr_addr_rclk) );
-
- gray_send #(.WIDTH(AWIDTH)) send_rd_addr
- (.clk_in(rclk),.addr_in(rd_addr),
- .clk_out(wclk),.addr_out(rd_addr_wclk) );
-
- // Generate fullness info, these are approximate and may be delayed
- // and are only for higher-level flow control.
- // Only full and empty are guaranteed exact.
- always @(posedge wclk)
- level_wclk <= wr_addr - rd_addr_wclk;
- always @(posedge rclk)
- level_rclk <= wr_addr_rclk - rd_addr;
-
-endmodule // fifo_2clock