diff options
Diffstat (limited to 'usrp2/fpga/control_lib/fifo_2clock.v')
-rw-r--r-- | usrp2/fpga/control_lib/fifo_2clock.v | 66 |
1 files changed, 0 insertions, 66 deletions
diff --git a/usrp2/fpga/control_lib/fifo_2clock.v b/usrp2/fpga/control_lib/fifo_2clock.v deleted file mode 100644 index 6b1eb607e..000000000 --- a/usrp2/fpga/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 |