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-rw-r--r--usrp2/control_lib/nsgpio.v107
1 files changed, 107 insertions, 0 deletions
diff --git a/usrp2/control_lib/nsgpio.v b/usrp2/control_lib/nsgpio.v
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+// 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 nsgpio
+ (input clk_i, input rst_i,
+ input cyc_i, input stb_i, input [3:0] adr_i, input we_i, input [31:0] dat_i,
+ output reg [31:0] 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[3:2] )
+ 2'b00 :
+ line <= dat_i;
+ 2'b01 :
+ ddr[31:0] <= dat_i;
+ 2'b10 :
+ ctrl[63:32] <= dat_i;
+ 2'b11 :
+ ctrl[31:0] <= dat_i;
+ endcase // case( adr_i[3:2] )
+
+ always @(posedge clk_i)
+ case (adr_i[3:2])
+ 2'b00 :
+ dat_o <= lgpio;
+ 2'b01 :
+ dat_o <= ddr;
+ 2'b10 :
+ dat_o <= ctrl[63:32];
+ 2'b11 :
+ dat_o <= ctrl[31:0];
+ endcase // case(adr_i[3:2])
+
+ 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
+