Merge branch 'fpga_next' into uhd_next

1 files changed, 95 insertions, 0 deletions

diff --git a/fpga/usrp2/gpif/gpif_wr.v b/fpga/usrp2/gpif/gpif_wr.v
new file mode 100644
index 000000000..89fae282e
--- /dev/null
+++ b/fpga/usrp2/gpif/gpif_wr.v
@@ -0,0 +1,95 @@
+//
+// Copyright 2011 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+
+module gpif_wr
+  (input gpif_clk, input gpif_rst,
+   input [15:0] gpif_data, input gpif_wr, input gpif_ep,
+   output reg gpif_full_d, output reg gpif_full_c,
+
+   input sys_clk, input sys_rst,
+   output [18:0] data_o, output src_rdy_o, input dst_rdy_i,
+   output [18:0] ctrl_o, output ctrl_src_rdy_o, input ctrl_dst_rdy_i,
+   output [31:0] debug );
+
+   reg 		 wr_reg, ep_reg;
+   reg [15:0] 	 gpif_data_reg;
+   
+   always @(posedge gpif_clk)
+     begin
+	ep_reg <= gpif_ep;
+	wr_reg <= gpif_wr;
+	gpif_data_reg <= gpif_data;
+     end
+
+   reg [9:0] write_count;
+   
+   always @(posedge gpif_clk)
+     if(gpif_rst)
+       write_count <= 0;
+     else if(wr_reg)
+       write_count <= write_count + 1;
+     else
+       write_count <= 0;
+
+   reg 	     sop;
+   wire      eop = (write_count == 255);
+   wire      eop_ctrl = (write_count == 15);
+   
+   always @(posedge gpif_clk)
+     sop <= gpif_wr & ~wr_reg;
+
+   // Data Path
+   wire [15:0] fifo_space;
+   always @(posedge gpif_clk)
+     if(gpif_rst)
+       gpif_full_d <= 1;
+     else
+       gpif_full_d <= fifo_space < 256;
+
+   wire [17:0] data_int;
+   wire        src_rdy_int, dst_rdy_int;
+
+   fifo_cascade #(.WIDTH(18), .SIZE(10)) wr_fifo
+     (.clk(gpif_clk), .reset(gpif_rst), .clear(0),
+      .datain({eop,sop,gpif_data_reg}), .src_rdy_i(~ep_reg & wr_reg & ~write_count[8]), .dst_rdy_o(), .space(fifo_space),
+      .dataout(data_int), .src_rdy_o(src_rdy_int), .dst_rdy_i(dst_rdy_int), .occupied());
+   
+   fifo_2clock_cascade #(.WIDTH(18), .SIZE(4)) wr_fifo_2clk
+     (.wclk(gpif_clk), .datain(data_int), .src_rdy_i(src_rdy_int), .dst_rdy_o(dst_rdy_int), .space(),
+      .rclk(sys_clk), .dataout(data_o[17:0]), .src_rdy_o(src_rdy_o), .dst_rdy_i(dst_rdy_i), .occupied(),
+      .arst(sys_rst));
+   assign data_o[18] = 1'b0;
+   
+   // Control Path
+   wire [15:0] ctrl_fifo_space;
+   always @(posedge gpif_clk)
+     if(gpif_rst)
+       gpif_full_c <= 1;
+     else
+       gpif_full_c <= ctrl_fifo_space < 16;
+   
+   fifo_2clock_cascade #(.WIDTH(19), .SIZE(4)) ctrl_fifo_2clk
+     (.wclk(gpif_clk), .datain({1'b0,eop_ctrl,sop,gpif_data_reg}), 
+      .src_rdy_i(ep_reg & wr_reg & ~write_count[4]), .dst_rdy_o(), .space(ctrl_fifo_space),
+      .rclk(sys_clk), .dataout(ctrl_o[18:0]), 
+      .src_rdy_o(ctrl_src_rdy_o), .dst_rdy_i(ctrl_dst_rdy_i), .occupied(),
+      .arst(sys_rst));
+
+   assign debug = { 16'd0, ep_reg, wr_reg, eop, sop, (~ep_reg & wr_reg & ~write_count[8]), src_rdy_int, dst_rdy_int, write_count[8:0]};
+   
+endmodule // gpif_wr