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//////////////////////////////////////////////////////////////////////////////////
module gpmc_async
#(parameter TXFIFOSIZE = 11, parameter RXFIFOSIZE = 11)
(// 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 reg 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,
input [15:0] tx_frame_len, output [15:0] rx_frame_len,
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;
always @(posedge fifo_clk)
if(fifo_rst)
bus_error <= 0;
else
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;
wire [35:0] tx36_data;
wire tx36_src_rdy, tx36_dst_rdy;
gpmc_to_fifo_async gpmc_to_fifo_async
(.EM_D(EM_D), .EM_NBE(EM_NBE), .EM_NCS(EM_NCS4), .EM_NWE(EM_NWE),
.fifo_clk(fifo_clk), .fifo_rst(fifo_rst),
.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_cascade #(.WIDTH(18), .SIZE(10)) tx_fifo
(.clk(fifo_clk), .reset(fifo_rst), .clear(0),
.datain(tx18_data), .src_rdy_i(tx18_src_rdy), .dst_rdy_o(tx18_dst_rdy), .space(tx_fifo_space),
.dataout(tx18b_data), .src_rdy_o(tx18b_src_rdy), .dst_rdy_i(tx18b_dst_rdy), .occupied());
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(tx36_data), .f36_src_rdy_o(tx36_src_rdy), .f36_dst_rdy_i(tx36_dst_rdy));
fifo_cascade #(.WIDTH(36), .SIZE(TXFIFOSIZE)) tx_fifo36
(.clk(wb_clk), .reset(wb_rst), .clear(0),
.datain(tx36_data), .src_rdy_i(tx36_src_rdy), .dst_rdy_o(tx36_dst_rdy),
.dataout(tx_data_o), .src_rdy_o(tx_src_rdy_o), .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;
wire [35:0] rx36_data;
wire rx36_src_rdy, rx36_dst_rdy;
wire dummy;
fifo_cascade #(.WIDTH(36), .SIZE(RXFIFOSIZE)) rx_fifo36
(.clk(wb_clk), .reset(wb_rst), .clear(0),
.datain(rx_data_i), .src_rdy_i(rx_src_rdy_i), .dst_rdy_o(rx_dst_rdy_o),
.dataout(rx36_data), .src_rdy_o(rx36_src_rdy), .dst_rdy_i(rx36_dst_rdy));
fifo36_to_fifo19 #(.LE(1)) f36_to_f19 // Little endian because ARM is LE
(.clk(fifo_clk), .reset(fifo_rst), .clear(0),
.f36_datain(rx36_data), .f36_src_rdy_i(rx36_src_rdy), .f36_dst_rdy_o(rx36_dst_rdy),
.f19_dataout({dummy,rx18_data}), .f19_src_rdy_o(rx18_src_rdy), .f19_dst_rdy_i(rx18_dst_rdy) );
fifo_cascade #(.WIDTH(18), .SIZE(12)) rx_fifo
(.clk(fifo_clk), .reset(fifo_rst), .clear(0),
.datain(rx18_data), .src_rdy_i(rx18_src_rdy), .dst_rdy_o(rx18_dst_rdy), .space(rx_fifo_space),
.dataout(rx18b_data), .src_rdy_o(rx18b_src_rdy), .dst_rdy_i(rx18b_dst_rdy), .occupied());
fifo_to_gpmc_async fifo_to_gpmc_async
(.clk(fifo_clk), .reset(fifo_rst), .clear(0),
.data_i(rx18b_data), .src_rdy_i(rx18b_src_rdy), .dst_rdy_o(rx18b_dst_rdy),
.EM_D(EM_D_fifo), .EM_NCS(EM_NCS4), .EM_NOE(EM_NOE),
.frame_len(rx_frame_len) );
fifo_watcher fifo_watcher
(.clk(fifo_clk), .reset(fifo_rst), .clear(0),
.src_rdy1(rx18_src_rdy), .dst_rdy1(rx18_dst_rdy), .sof1(rx18_data[16]), .eof1(rx18_data[17]),
.src_rdy2(rx18b_src_rdy), .dst_rdy2(rx18b_dst_rdy), .sof2(rx18b_data[16]), .eof2(rx18b_data[17]),
.have_packet(rx_have_data), .length(rx_frame_len), .bus_error(bus_error_rx) );
// ////////////////////////////////////////////
// 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_async
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