Modified nsgpio.v to support 16 bit little endian bus interface.

1 files changed, 124 insertions, 0 deletions

diff --git a/usrp2/control_lib/nsgpio16LE.v b/usrp2/control_lib/nsgpio16LE.v
new file mode 100644
index 000000000..6847bb4a9
--- /dev/null
+++ b/usrp2/control_lib/nsgpio16LE.v
@@ -0,0 +1,124 @@
+// Modified from code originally by Richard Herveille, his copyright is below
+
+/////////////////////////////////////////////////////////////////////
+////                                                             ////
+////  OpenCores Simple General Purpose IO core                   ////
+////                                                             ////
+////  Author: Richard Herveille                                  ////
+////          richard@asics.ws                                   ////
+////          www.asics.ws                                       ////
+////                                                             ////
+/////////////////////////////////////////////////////////////////////
+////                                                             ////
+//// Copyright (C) 2002 Richard Herveille                        ////
+////                    richard@asics.ws                         ////
+////                                                             ////
+//// This source file may be used and distributed without        ////
+//// restriction provided that this copyright statement is not   ////
+//// removed from the file and that any derivative work contains ////
+//// the original copyright notice and the associated disclaimer.////
+////                                                             ////
+////     THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY     ////
+//// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED   ////
+//// TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS   ////
+//// FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL THE AUTHOR      ////
+//// OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,         ////
+//// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES    ////
+//// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE   ////
+//// GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR        ////
+//// BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF  ////
+//// LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT  ////
+//// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT  ////
+//// OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE         ////
+//// POSSIBILITY OF SUCH DAMAGE.                                 ////
+////                                                             ////
+/////////////////////////////////////////////////////////////////////
+
+
+module nsgpio16LE
+  (input clk_i, input rst_i, 
+   input cyc_i, input stb_i, input [3:0] adr_i, input we_i, input [15:0] dat_i, 
+   output reg [15:0] dat_o, output reg ack_o,
+   input [31:0] atr, input [31:0] debug_0, input [31:0] debug_1, 
+   inout [31:0] gpio
+   );
+
+   reg [63:0] 	ctrl;
+   reg [31:0] 	line;
+   reg [31:0] 	lgpio;               // LatchedGPIO pins
+   reg [31:0] 	ddr;
+   
+   wire 	wb_acc = cyc_i & stb_i;            // WISHBONE access
+   wire 	wb_wr  = wb_acc & we_i;            // WISHBONE write access
+
+   always @(posedge clk_i or posedge rst_i)
+     if (rst_i)
+       begin
+          ctrl <= 64'h0;
+          line <= 0;
+       end
+     else if (wb_wr)
+       case( adr_i[3:1] )
+	 3'b000 : 
+           line[15:0] <= dat_i;
+	 3'b001 : 
+           line[31:16] <= dat_i;
+	 3'b010 :
+	   ddr[15:0] <= dat_i;
+	 3'b011 :
+	   ddr[31:16] <= dat_i;
+	 3'b100 :
+	   ctrl[15:0] <= dat_i;
+	 3'b101 :
+	   ctrl[31:16] <= dat_i;
+	 3'b110 :
+	   ctrl[47:32] <= dat_i;
+	 3'b111 :
+	   ctrl[63:48] <= dat_i;
+       endcase // case ( adr_i[3:1] )
+   
+   always @(posedge clk_i)
+     case (adr_i[3:1])
+       3'b000 :
+	 dat_o <= lgpio[15:0];
+       3'b001 :
+	 dat_o <= lgpio[31:16];
+       3'b010 :
+	 dat_o <= ddr[15:0];
+       3'b011 :
+	 dat_o <= ddr[31:16];
+       3'b100 :
+	 dat_o <= ctrl[15:0];
+       3'b101 :
+	 dat_o <= ctrl[31:16];
+       3'b110 :
+	 dat_o <= ctrl[47:32];
+       3'b111 :
+	 dat_o <= ctrl[63:48];
+     endcase // case (adr_i[3:1])
+   
+   
+   always @(posedge clk_i or posedge rst_i)
+     if (rst_i)
+       ack_o <= 1'b0;
+     else
+       ack_o <= wb_acc & !ack_o;
+   
+   // latch GPIO input pins
+   always @(posedge clk_i)
+     lgpio <= gpio;
+   
+   // assign GPIO outputs
+   integer   n;
+   reg [31:0] igpio; // temporary internal signal
+   
+   always @(ctrl or line or debug_1 or debug_0 or atr)
+     for(n=0;n<32;n=n+1)
+       igpio[n] <= ddr[n] ? (ctrl[2*n+1] ? (ctrl[2*n] ? debug_1[n] : debug_0[n]) : 
+			     (ctrl[2*n] ?  atr[n] : line[n]) )
+	 : 1'bz;
+   
+   assign     gpio = igpio;
+   
+endmodule
+