Merge remote branch 'origin/usrp_e_next' into usrp_e_next

1 files changed, 46 insertions, 0 deletions

diff --git a/fpga/usrp2/gpmc/ram_to_fifo.v b/fpga/usrp2/gpmc/ram_to_fifo.v
new file mode 100644
index 000000000..8549dcc35
--- /dev/null
+++ b/fpga/usrp2/gpmc/ram_to_fifo.v
@@ -0,0 +1,46 @@
+
+
+module ram_to_fifo
+  (input clk, input reset,
+   input [10:0] read_length,  // From the dbsm (?)
+   output read_en, output reg [8:0] read_addr, input [31:0] read_data, input read_ready, output read_done,
+   output [35:0] data_o, output src_rdy_o, input dst_rdy_i);
+
+   // read_length/2 = number of 32 bit lines, numbered 0 through read_length/2-1
+   wire [8:0] 	 last_line = (read_length[10:1]-1); 
+
+   reg 		 read_phase, sop;
+
+   assign read_en = (read_phase == 0) | dst_rdy_i;
+   assign src_rdy_o = (read_phase == 1);
+   
+   always @(posedge clk)
+     if(reset)
+       begin
+	  read_addr <= 0;
+	  read_phase <= 0;
+	  sop <= 1;
+       end
+     else
+       if(read_phase == 0)
+	 begin
+	    read_addr <= read_ready;
+	    read_phase <= read_ready;
+	 end
+       else if(dst_rdy_i)
+	 begin
+	    sop <= 0;
+	    if(read_addr == last_line)
+	      begin
+		 read_addr <= 0;
+		 read_phase <= 0;
+	      end
+	    else
+	      read_addr <= read_addr + 1;
+	 end
+   
+   assign read_done = (read_phase == 1) & (read_addr == last_line) & dst_rdy_i;
+   wire eop = (read_addr == last_line);
+   assign data_o = { 2'b00, eop, sop, read_data };
+   
+endmodule // ram_to_fifo