1 files changed, 123 insertions, 0 deletions
diff --git a/fpga/usrp3/top/x400/ipass_present_controller.v b/fpga/usrp3/top/x400/ipass_present_controller.v
new file mode 100644
index 000000000..020aecf36
--- /dev/null
+++ b/fpga/usrp3/top/x400/ipass_present_controller.v
@@ -0,0 +1,123 @@
+//
+// Copyright 2021 Ettus Research, A National Instruments Brand
+//
+// SPDX-License-Identifier: LGPL-3.0-or-later
+//
+// Module: ipass_present_controller
+//
+// Description:
+//
+//   Translate the iPass present signals on FPGA to control port requests in
+//   order to transfer them to the MB CPLD, which needs it for PCIe reset
+//   generation.
+//
+
+`default_nettype none
+
+
+module ipass_present_controller (
+  // Common ControlPort signals
+  input wire ctrlport_clk,
+  input wire ctrlport_rst,
+
+  // ControlPort request
+  output  reg        m_ctrlport_req_wr,
+  output wire        m_ctrlport_req_rd,
+  output wire [19:0] m_ctrlport_req_addr,
+  output wire [31:0] m_ctrlport_req_data,
+  output wire [ 3:0] m_ctrlport_req_byte_en,
+
+  // ControlPort response
+  input  wire        m_ctrlport_resp_ack,
+  input  wire [ 1:0] m_ctrlport_resp_status,
+  input  wire [31:0] m_ctrlport_resp_data,
+
+  // Configuration
+  input  wire        enable,
+
+  // Asynchronous ipass present signals
+  input  wire [ 1:0] ipass_present_n
+);
+
+`include "regmap/pl_cpld_regmap_utils.vh"
+`include "cpld/regmap/mb_cpld_pl_regmap_utils.vh"
+`include "cpld/regmap/pl_cpld_base_regmap_utils.vh"
+`include "../../lib/rfnoc/core/ctrlport.vh"
+
+//-----------------------------------------------------------------------------
+// Transfer iPass signals to local clock domain
+//-----------------------------------------------------------------------------
+
+wire [1:0] ipass_present;
+wire [1:0] ipass_present_lcl;
+
+assign ipass_present = ~ipass_present_n;
+
+synchronizer #(
+  .WIDTH            (2),
+  .STAGES           (2),
+  .INITIAL_VAL      (0),
+  .FALSE_PATH_TO_IN (1)
+) synchronizer_i (
+  .clk (ctrlport_clk),
+  .rst (ctrlport_rst),
+  .in  (ipass_present),
+  .out (ipass_present_lcl)
+); 
+
+//-----------------------------------------------------------------------------
+// Logic to wait for response after trigging request
+//-----------------------------------------------------------------------------
+
+reg transfer_in_progress  = 1'b0;
+reg error_occurred        = 1'b0;
+reg enable_delayed        = 1'b0;
+reg [1:0] ipass_present_cached = 2'b0;
+
+// Rising-edge detection on enable signal
+wire activated;
+assign activated = enable & ~enable_delayed;
+
+always @(posedge ctrlport_clk) begin
+  if (ctrlport_rst) begin
+    m_ctrlport_req_wr    <= 1'b0;
+    transfer_in_progress <= 1'b0;
+    enable_delayed       <= 1'b0;
+    error_occurred       <= 1'b0;
+    ipass_present_cached <= 2'b0;
+  end else begin
+    // Default assignment
+    m_ctrlport_req_wr <= 1'b0;
+    enable_delayed    <= enable;
+
+    // Issue new request on change if no request is pending
+    if (((ipass_present_lcl != ipass_present_cached) || error_occurred || activated)
+      && ~transfer_in_progress && enable) begin
+      transfer_in_progress <= 1'b1;
+      m_ctrlport_req_wr    <= 1'b1;
+      ipass_present_cached <= ipass_present_lcl;
+    end
+
+    // Reset pending request
+    if (m_ctrlport_resp_ack) begin
+      transfer_in_progress <= 1'b0;
+      error_occurred       <= m_ctrlport_resp_status != CTRL_STS_OKAY;
+    end
+  end
+end
+
+//-----------------------------------------------------------------------------
+// Static ControlPort assignments
+//-----------------------------------------------------------------------------
+
+assign m_ctrlport_req_rd      = 1'b0;
+assign m_ctrlport_req_byte_en = 4'b1111;
+assign m_ctrlport_req_addr    = MB_CPLD + PL_REGISTERS + CABLE_PRESENT_REG;
+assign m_ctrlport_req_data    = 32'b0 |
+                                (ipass_present_cached[0] << IPASS0_CABLE_PRESENT) |
+                                (ipass_present_cached[1] << IPASS1_CABLE_PRESENT);
+
+endmodule
+
+
+`default_nettype wire