summaryrefslogtreecommitdiffstats
path: root/fpga/usrp2/gpmc/gpmc.v
blob: 2ba69d184b848597ac40c2d28ae36e973fd4466b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
//
// Copyright 2011-2012 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 gpmc
  #(parameter TXFIFOSIZE = 11,
    parameter RXFIFOSIZE = 11,
    parameter ADDR_WIDTH = 10,
    parameter BUSDEBUG = 1)
   (// GPMC signals
    input arst,
    input EM_CLK, inout [15:0] EM_D, input [ADDR_WIDTH:1] EM_A, input [1:0] EM_NBE,
    input EM_WAIT0, input EM_NCS4, input EM_NCS6, input EM_NWE, input EM_NOE,

    // GPIOs for FIFO signalling
    output rx_have_data, output tx_have_space, output resp_have_data,

    // FIFO interface
    input fifo_clk, input fifo_rst,
    output [35:0] tx_data, output tx_src_rdy, input tx_dst_rdy,
    input [35:0] rx_data, input rx_src_rdy, output rx_dst_rdy,
    output [35:0] ctrl_data, output ctrl_src_rdy, input ctrl_dst_rdy,
    input [35:0] resp_data, input resp_src_rdy, output resp_dst_rdy,

    output [31:0] debug
    );

   wire EM_output_enable = (~EM_NOE & (~EM_NCS4 | ~EM_NCS6));
   wire [15:0] 	  EM_D_data;
   wire [15:0] 	  EM_D_ctrl;

   assign EM_D = ~EM_output_enable ? 16'bz : ~EM_NCS4 ? EM_D_data : EM_D_ctrl;

   // CS4 is RAM_2PORT for DATA PATH (high-speed data)
   //    Writes go into one RAM, reads come from the other
   // CS6 is for CONTROL PATH (slow)

   // ////////////////////////////////////////////
   // TX Data Path

   wire [17:0] 	  tx18_data;
   wire 	  tx18_src_rdy, tx18_dst_rdy;
   wire [35:0] 	  txb_data;
   wire 	  txb_src_rdy, txb_dst_rdy;

   gpmc_to_fifo #(.ADDR_WIDTH(ADDR_WIDTH)) gpmc_to_fifo
     (.EM_D(EM_D), .EM_A(EM_A), .EM_CLK(EM_CLK), .EM_WE(~EM_NCS4 & ~EM_NWE),
      .clk(fifo_clk), .reset(fifo_rst), .clear(1'b0), .arst(fifo_rst | arst),
      .data_o(tx18_data), .src_rdy_o(tx18_src_rdy), .dst_rdy_i(tx18_dst_rdy),
      .have_space(tx_have_space));

   fifo19_to_fifo36 #(.LE(1)) f19_to_f36   // Little endian because ARM is LE
     (.clk(fifo_clk), .reset(fifo_rst), .clear(1'b0),
      .f19_datain({1'b0,tx18_data}), .f19_src_rdy_i(tx18_src_rdy), .f19_dst_rdy_o(tx18_dst_rdy),
      .f36_dataout(txb_data), .f36_src_rdy_o(txb_src_rdy), .f36_dst_rdy_i(txb_dst_rdy));

   fifo_cascade #(.WIDTH(36), .SIZE(TXFIFOSIZE)) tx_buffering(
        .clk(fifo_clk), .reset(fifo_rst), .clear(1'b0),
        .datain(txb_data), .src_rdy_i(txb_src_rdy), .dst_rdy_o(txb_dst_rdy),
        .dataout(tx_data), .src_rdy_o(tx_src_rdy), .dst_rdy_i(tx_dst_rdy)
   );

   // ////////////////////////////////////////////
   // RX Data Path
   
   wire [17:0] 	  rx18_data;
   wire 	  rx18_src_rdy, rx18_dst_rdy;
   wire [35:0] 	  rxb_data;
   wire 	  rxb_src_rdy, rxb_dst_rdy;
   wire 	  dummy;

   fifo_cascade #(.WIDTH(36), .SIZE(RXFIFOSIZE)) rx_buffering(
        .clk(fifo_clk), .reset(fifo_rst), .clear(1'b0),
        .datain(rx_data), .src_rdy_i(rx_src_rdy), .dst_rdy_o(rx_dst_rdy),
        .dataout(rxb_data), .src_rdy_o(rxb_src_rdy), .dst_rdy_i(rxb_dst_rdy)
   );

   fifo36_to_fifo19 #(.LE(1)) f36_to_f19   // Little endian because ARM is LE
     (.clk(fifo_clk), .reset(fifo_rst), .clear(1'b0),
      .f36_datain(rxb_data), .f36_src_rdy_i(rxb_src_rdy), .f36_dst_rdy_o(rxb_dst_rdy),
      .f19_dataout({dummy,rx18_data}), .f19_src_rdy_o(rx18_src_rdy), .f19_dst_rdy_i(rx18_dst_rdy) );

   fifo_to_gpmc #(.ADDR_WIDTH(ADDR_WIDTH), .LAST_ADDR(10'h3ff)) fifo_to_gpmc
     (.clk(fifo_clk), .reset(fifo_rst), .clear(1'b0), .arst(fifo_rst | arst),
      .data_i(rx18_data), .src_rdy_i(rx18_src_rdy), .dst_rdy_o(rx18_dst_rdy),
      .EM_D(EM_D_data), .EM_A(EM_A), .EM_CLK(EM_CLK), .EM_OE(~EM_NCS4 & ~EM_NOE),
      .data_available(rx_have_data));

   // ////////////////////////////////////////////
   // Control path on CS6

   // ////////////////////////////////////////////////////////////////////
   // CTRL TX Data Path

   wire [17:0] 	  ctrl18_data;
   wire 	  ctrl18_src_rdy, ctrl18_dst_rdy;
   wire [35:0] 	  ctrlb_data;
   wire 	  ctrlb_src_rdy, ctrlb_dst_rdy;

   gpmc_to_fifo #(.PTR_WIDTH(5), .ADDR_WIDTH(5)) ctrl_gpmc_to_fifo
     (.EM_D(EM_D), .EM_A(EM_A[5:1]), .EM_CLK(EM_CLK), .EM_WE(~EM_NCS6 & ~EM_NWE & (EM_A[ADDR_WIDTH:6] == 0)),
      .clk(fifo_clk), .reset(fifo_rst), .clear(1'b0), .arst(fifo_rst | arst),
      .data_o(ctrl18_data), .src_rdy_o(ctrl18_src_rdy), .dst_rdy_i(ctrl18_dst_rdy),
      .have_space(/*always*/));

   fifo19_to_fifo36 #(.LE(1)) ctrl_f19_to_f36   // Little endian because ARM is LE
     (.clk(fifo_clk), .reset(fifo_rst), .clear(1'b0),
      .f19_datain({1'b0,ctrl18_data}), .f19_src_rdy_i(ctrl18_src_rdy), .f19_dst_rdy_o(ctrl18_dst_rdy),
      .f36_dataout(ctrlb_data), .f36_src_rdy_o(ctrlb_src_rdy), .f36_dst_rdy_i(ctrlb_dst_rdy));

   fifo_cascade #(.WIDTH(36), .SIZE(9)) ctrl_buffering(
        .clk(fifo_clk), .reset(fifo_rst), .clear(1'b0),
        .datain(ctrlb_data), .src_rdy_i(ctrlb_src_rdy), .dst_rdy_o(ctrlb_dst_rdy),
        .dataout(ctrl_data), .src_rdy_o(ctrl_src_rdy), .dst_rdy_i(ctrl_dst_rdy)
   );

   // ////////////////////////////////////////////
   // CTRL RX Data Path

   wire [17:0] 	  resp18_data;
   wire 	  resp18_src_rdy, resp18_dst_rdy;
   wire [35:0] 	  respb_data;
   wire 	  respb_src_rdy, respb_dst_rdy;
   wire 	  resp_dummy;

   fifo_cascade #(.WIDTH(36), .SIZE(9)) resp_buffering(
        .clk(fifo_clk), .reset(fifo_rst), .clear(1'b0),
        .datain(resp_data), .src_rdy_i(resp_src_rdy), .dst_rdy_o(resp_dst_rdy),
        .dataout(respb_data), .src_rdy_o(respb_src_rdy), .dst_rdy_i(respb_dst_rdy)
   );

   fifo36_to_fifo19 #(.LE(1)) resp_f36_to_f19   // Little endian because ARM is LE
     (.clk(fifo_clk), .reset(fifo_rst), .clear(1'b0),
      .f36_datain(respb_data), .f36_src_rdy_i(respb_src_rdy), .f36_dst_rdy_o(respb_dst_rdy),
      .f19_dataout({resp_dummy,resp18_data}), .f19_src_rdy_o(resp18_src_rdy), .f19_dst_rdy_i(resp18_dst_rdy) );

   fifo_to_gpmc #(.ADDR_WIDTH(ADDR_WIDTH), .LAST_ADDR(10'h00f)) resp_fifo_to_gpmc
     (.clk(fifo_clk), .reset(fifo_rst), .clear(1'b0), .arst(fifo_rst | arst),
      .data_i(resp18_data), .src_rdy_i(resp18_src_rdy), .dst_rdy_o(resp18_dst_rdy),
      .EM_D(EM_D_ctrl), .EM_A(EM_A), .EM_CLK(EM_CLK), .EM_OE(~EM_NCS6 & ~EM_NOE),
      .data_available(resp_have_data));

    assign debug = {
        EM_D,
        //resp18_data[15:0], //16
        EM_A, //10
        //resp18_data[17:16], resp18_src_rdy, resp18_dst_rdy, //4
        EM_NCS4, EM_NCS6, EM_NWE, EM_NOE, //4
        EM_CLK, resp_have_data //2
    };

endmodule // gpmc