diff options
Diffstat (limited to 'fpga/usrp2/control_lib/nsgpio.v')
| -rw-r--r-- | fpga/usrp2/control_lib/nsgpio.v | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/fpga/usrp2/control_lib/nsgpio.v b/fpga/usrp2/control_lib/nsgpio.v new file mode 100644 index 000000000..6c6873fee --- /dev/null +++ b/fpga/usrp2/control_lib/nsgpio.v @@ -0,0 +1,93 @@ +// 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 [4:0] adr_i, input we_i, input [31:0] dat_i, + output reg [31:0] dat_o, output reg ack_o, + input tx, input rx, inout [31:0] gpio + ); + + integer n; + reg [31:0] ddr; + reg [31:0] idle_out, rx_out, tx_out, fdx_out; + reg [31:0] rgpio, igpio; + + 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) + ddr <= 0; + else if (wb_wr) + case( adr_i[4:2] ) + 3'b000 : + idle_out <= dat_i; + 3'b001 : + rx_out <= dat_i; + 3'b010 : + tx_out <= dat_i; + 3'b011 : + fdx_out <= dat_i; + 3'b100 : + ddr <= dat_i; + endcase // case ( adr_i[4:2] ) + + always @(posedge clk_i) + dat_o <= gpio; + + always @(posedge clk_i or posedge rst_i) + if (rst_i) + ack_o <= 1'b0; + else + ack_o <= wb_acc & !ack_o; + + always @(posedge clk_i) + case({tx,rx}) + 2'b00 : rgpio <= idle_out; + 2'b01 : rgpio <= rx_out; + 2'b10 : rgpio <= tx_out; + 2'b11 : rgpio <= fdx_out; + endcase // case ({tx,rx}) + + always @* + for(n=0;n<32;n=n+1) + igpio[n] <= ddr[n] ? rgpio[n] : 1'bz; + + assign gpio = igpio; + +endmodule |