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-rw-r--r--control_lib/newfifo/fifo36_to_ll8.v60
1 files changed, 60 insertions, 0 deletions
diff --git a/control_lib/newfifo/fifo36_to_ll8.v b/control_lib/newfifo/fifo36_to_ll8.v
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+++ b/control_lib/newfifo/fifo36_to_ll8.v
@@ -0,0 +1,60 @@
+
+module fifo36_to_ll8
+ (input clk, reset,
+ input [35:0] f36_data,
+ input f36_src_rdy_i,
+ output f36_dst_rdy_o,
+
+ output reg [7:0] ll_data,
+ output ll_sof_n,
+ output ll_eof_n,
+ output ll_src_rdy_n,
+ input ll_dst_rdy_n,
+
+ output [31:0] debug);
+
+ wire ll_sof, ll_eof, ll_src_rdy;
+ assign ll_sof_n = ~ll_sof;
+ assign ll_eof_n = ~ll_eof;
+ assign ll_src_rdy_n = ~ll_src_rdy;
+ wire ll_dst_rdy = ~ll_dst_rdy_n;
+
+ wire f36_sof = f36_data[32];
+ wire f36_eof = f36_data[33];
+ wire f36_occ = f36_data[35:34];
+ wire advance, end_early;
+ reg [1:0] state;
+ assign debug = {29'b0,state};
+
+ always @(posedge clk)
+ if(reset)
+ state <= 0;
+ else
+ if(advance)
+ if(ll_eof)
+ state <= 0;
+ else
+ state <= state + 1;
+
+ always @*
+ case(state)
+ 0 : ll_data = f36_data[31:24];
+ 1 : ll_data = f36_data[23:16];
+ 2 : ll_data = f36_data[15:8];
+ 3 : ll_data = f36_data[7:0];
+ default : ll_data = f36_data[31:24];
+ endcase // case (state)
+
+ assign ll_sof = (state==0) & f36_sof;
+ assign ll_eof = f36_eof & (((state==0)&(f36_occ==1)) |
+ ((state==1)&(f36_occ==2)) |
+ ((state==2)&(f36_occ==3)) |
+ (state==3));
+
+ assign ll_src_rdy = f36_src_rdy_i;
+
+ assign advance = ll_src_rdy & ll_dst_rdy;
+ assign f36_dst_rdy_o = advance & ((state==3)|ll_eof);
+ assign debug = state;
+
+endmodule // ll8_to_fifo36