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module gpif_wr
(input gpif_clk, input gpif_rst,
input [15:0] gpif_data, input gpif_wr,
output reg have_space,
input sys_clk, input sys_rst,
output [18:0] data_o, output src_rdy_o, input dst_rdy_i,
output [31:0] debug );
reg wr_reg;
reg [15:0] gpif_data_reg;
always @(posedge gpif_clk)
begin
wr_reg <= gpif_wr;
gpif_data_reg <= gpif_data;
end
reg [9:0] write_count;
always @(posedge gpif_clk)
if(gpif_rst)
write_count <= 0;
else if(wr_reg)
write_count <= write_count + 1;
else
write_count <= 0;
reg sop;
wire eop = (write_count == 255);
always @(posedge gpif_clk)
sop <= gpif_wr & ~wr_reg;
wire [15:0] fifo_space;
always @(posedge gpif_clk)
have_space <= fifo_space > 256;
wire [17:0] data_int;
wire src_rdy_int, dst_rdy_int;
fifo_cascade #(.WIDTH(18), .SIZE(9)) wr_fifo
(.clk(gpif_clk), .reset(gpif_rst), .clear(0),
.datain({eop,sop,gpif_data_reg}), .src_rdy_i(wr_reg & ~write_count[8]), .dst_rdy_o(), .space(fifo_space),
.dataout(data_int), .src_rdy_o(src_rdy_int), .dst_rdy_i(dst_rdy_int), .occupied());
fifo_2clock_cascade #(.WIDTH(18), .SIZE(4)) wr_fifo_2clk
(.wclk(gpif_clk), .datain(data_int), .src_rdy_i(src_rdy_int), .dst_rdy_o(dst_rdy_int), .space(),
.rclk(sys_clk), .dataout(data_o[17:0]), .src_rdy_o(src_rdy_o), .dst_rdy_i(dst_rdy_i), .occupied(),
.arst(sys_rst));
assign data_o[18] = 0;
endmodule // gpif_wr
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