1 files changed, 113 insertions, 0 deletions
diff --git a/fpga/usrp2/models/cpld_model.v b/fpga/usrp2/models/cpld_model.v
new file mode 100644
index 000000000..900577852
--- /dev/null
+++ b/fpga/usrp2/models/cpld_model.v
@@ -0,0 +1,113 @@
+//
+// 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 cpld_model
+  (input aux_clk, input start, input mode, input done,
+   output dout, output reg sclk, output detached);
+
+   reg [7:0] rom[0:65535];
+
+   reg [15:0] addr;
+   reg [7:0]  data;
+   assign     dout = data[7];
+
+   reg [2:0]  state, bitcnt;
+   
+   localparam IDLE = 3'd0;
+   localparam READ = 3'd1;
+   localparam BIT1 = 3'd2;
+   localparam BIT2 = 3'd3;
+   localparam DONE = 3'd4;
+   localparam DETACHED = 3'd5;
+   localparam ERROR = 3'd7;
+   
+   integer i; 
+   reg [1023:0] ROMFile;
+   
+   initial begin
+      for (i=0;i<65536;i=i+1) begin
+	 rom[i] <= 32'h0;
+      end       
+      if ( !$value$plusargs( "rom=%s", ROMFile ) )
+        begin
+           $display( "Using default ROM file, 'flash.rom'" );
+           ROMFile = "flash.rom";
+        end
+      else
+	$display( "Using %s as ROM file.", ROMFile);
+      
+      #1 $readmemh( ROMFile,rom );     
+   end
+
+   initial addr = 16'd0;
+   initial data = 8'd0;
+   initial state = IDLE;
+   initial bitcnt = 3'd0;
+   initial sclk = 1'b0;
+   
+   always @(posedge aux_clk)
+     case(state)
+       IDLE :
+	 if(start)
+	   if(~mode)
+	     state <= READ;
+	   else
+	     state <= ERROR;
+       READ :
+	 if(done)
+	   state <= DONE;
+       	 else
+	   begin
+	      data <= rom[addr];
+	      addr <= addr + 1;
+	      bitcnt <= 3'd0;
+	      if(addr==16'hFFFF)
+		state <= ERROR;
+	      else
+		state <= BIT1;
+	   end // else: !if(start)
+       BIT1 :
+	 begin
+	    sclk <= 1'b1;
+	    state <= BIT2;
+	 end
+       BIT2 :
+	 begin
+	    sclk <= 1'b0;
+	    data <= {data[6:0],1'b0};
+	    bitcnt <= bitcnt + 1;
+	    if(bitcnt==7)
+	      state <= READ;
+	    else
+	      state <=BIT1;
+	 end
+       DONE :
+	 begin
+	    if(start)
+	      state <= ERROR;
+	    else
+	      state <= DETACHED;
+	 end
+       DETACHED :
+	 if(start)
+	   state <= ERROR;
+     endcase // case(state)
+   
+   assign detached = (state == DETACHED) || (state == IDLE);
+   
+endmodule // cpld_model