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-rw-r--r--fpga/usrp2/gpmc/gpmc_sync.v108
1 files changed, 108 insertions, 0 deletions
diff --git a/fpga/usrp2/gpmc/gpmc_sync.v b/fpga/usrp2/gpmc/gpmc_sync.v
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+++ b/fpga/usrp2/gpmc/gpmc_sync.v
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+//////////////////////////////////////////////////////////////////////////////////
+
+module gpmc_sync
+ (// GPMC signals
+ input arst,
+ input EM_CLK, inout [15:0] EM_D, input [10:1] 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 bus_error, input bus_reset,
+
+ // Wishbone signals
+ input wb_clk, input wb_rst,
+ output [10:0] wb_adr_o, output [15:0] wb_dat_mosi, input [15:0] wb_dat_miso,
+ output [1:0] wb_sel_o, output wb_cyc_o, output wb_stb_o, output wb_we_o, input wb_ack_i,
+
+ // FIFO interface
+ input fifo_clk, input fifo_rst,
+ output [35:0] tx_data_o, output tx_src_rdy_o, input tx_dst_rdy_i,
+ input [35:0] rx_data_i, input rx_src_rdy_i, output rx_dst_rdy_o,
+
+ output [31:0] debug
+ );
+
+ wire EM_output_enable = (~EM_NOE & (~EM_NCS4 | ~EM_NCS6));
+ wire [15:0] EM_D_fifo;
+ wire [15:0] EM_D_wb;
+
+ assign EM_D = ~EM_output_enable ? 16'bz : ~EM_NCS4 ? EM_D_fifo : EM_D_wb;
+
+ wire bus_error_tx, bus_error_rx;
+ assign bus_error = bus_error_tx | bus_error_rx;
+
+ // 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 (wishbone)
+
+ // ////////////////////////////////////////////
+ // TX Data Path
+
+ wire [17:0] tx18_data, tx18b_data;
+ wire tx18_src_rdy, tx18_dst_rdy, tx18b_src_rdy, tx18b_dst_rdy;
+ wire [15:0] tx_fifo_space, tx_frame_len;
+
+ assign tx_frame_len = 10;
+
+ gpmc_to_fifo_sync gpmc_to_fifo_sync
+ (.arst(arst),
+ .EM_CLK(EM_CLK), .EM_D(EM_D), .EM_NBE(EM_NBE), .EM_NCS(EM_NCS4), .EM_NWE(EM_NWE),
+ .data_o(tx18_data), .src_rdy_o(tx18_src_rdy), .dst_rdy_i(tx18_dst_rdy),
+ .frame_len(tx_frame_len), .fifo_space(tx_fifo_space), .fifo_ready(tx_have_space),
+ .bus_error(bus_error_tx) );
+
+ fifo_2clock_cascade #(.WIDTH(18), .SIZE(4)) tx_fifo
+ (.wclk(EM_CLK), .datain(tx18_data),
+ .src_rdy_i(tx18_src_rdy), .dst_rdy_o(tx18_dst_rdy), .space(tx_fifo_space),
+ .rclk(fifo_clk), .dataout(tx18b_data),
+ .src_rdy_o(tx18b_src_rdy), .dst_rdy_i(tx18b_dst_rdy), .occupied(), .arst(arst));
+
+ fifo19_to_fifo36 #(.LE(1)) f19_to_f36 // Little endian because ARM is LE
+ (.clk(fifo_clk), .reset(fifo_rst), .clear(0),
+ .f19_datain({1'b0,tx18b_data}), .f19_src_rdy_i(tx18b_src_rdy), .f19_dst_rdy_o(tx18b_dst_rdy),
+ .f36_dataout(tx_data_o), .f36_src_rdy_o(tx_src_rdy_o), .f36_dst_rdy_i(tx_dst_rdy_i));
+
+ // ////////////////////////////////////////////
+ // RX Data Path
+
+ wire [17:0] rx18_data, rx18b_data;
+ wire rx18_src_rdy, rx18_dst_rdy, rx18b_src_rdy, rx18b_dst_rdy;
+ wire [15:0] rx_fifo_space, rx_frame_len;
+ wire dummy;
+
+ fifo36_to_fifo19 #(.LE(1)) f36_to_f19 // Little endian because ARM is LE
+ (.clk(fifo_clk), .reset(fifo_rst), .clear(0),
+ .f36_datain(rx_data_i), .f36_src_rdy_i(rx_src_rdy_i), .f36_dst_rdy_o(rx_dst_rdy_o),
+ .f19_dataout({dummy,rx18_data}), .f19_src_rdy_o(rx18_src_rdy), .f19_dst_rdy_i(rx18_dst_rdy) );
+
+ fifo_2clock_cascade #(.WIDTH(18), .SIZE(10)) rx_fifo
+ (.wclk(fifo_clk), .datain(rx18_data),
+ .src_rdy_i(rx18_src_rdy), .dst_rdy_o(rx18_dst_rdy), .space(rx_fifo_space),
+ .rclk(EM_CLK), .dataout(rx18b_data),
+ .src_rdy_o(rx18b_src_rdy), .dst_rdy_i(rx18b_dst_rdy), .occupied(), .arst(arst));
+
+ fifo_to_gpmc_sync fifo_to_gpmc_sync
+ (.arst(arst),
+ .data_i(rx18b_data), .src_rdy_i(rx18b_src_rdy), .dst_rdy_o(rx18b_dst_rdy),
+ .EM_CLK(EM_CLK), .EM_D(EM_D_fifo), .EM_NCS(EM_NCS4), .EM_NOE(EM_NOE),
+ .fifo_ready(rx_have_data) );
+
+ fifo_watcher fifo_watcher
+ (.clk(fifo_clk), .reset(fifo_rst), .clear(0),
+ .src_rdy(rx18_src_rdy), .dst_rdy(rx18_dst_rdy), .sof(rx18_data[16]), .eof(rx18_data[17]),
+ .have_packet(), .length(), .next() );
+
+ // ////////////////////////////////////////////
+ // Control path on CS6
+
+ gpmc_wb gpmc_wb
+ (.EM_CLK(EM_CLK), .EM_D_in(EM_D), .EM_D_out(EM_D_wb), .EM_A(EM_A), .EM_NBE(EM_NBE),
+ .EM_NCS(EM_NCS6), .EM_NWE(EM_NWE), .EM_NOE(EM_NOE),
+ .wb_clk(wb_clk), .wb_rst(wb_rst),
+ .wb_adr_o(wb_adr_o), .wb_dat_mosi(wb_dat_mosi), .wb_dat_miso(wb_dat_miso),
+ .wb_sel_o(wb_sel_o), .wb_cyc_o(wb_cyc_o), .wb_stb_o(wb_stb_o), .wb_we_o(wb_we_o),
+ .wb_ack_i(wb_ack_i) );
+
+ assign debug = 0;
+
+endmodule // gpmc_sync