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authorJosh Blum <josh@joshknows.com>2010-04-16 09:42:46 +0000
committerJosh Blum <josh@joshknows.com>2010-04-16 09:42:46 +0000
commit835cb56ef820a69e1e6e0ccde7c5a0e78ca5ad25 (patch)
tree4fe48bdaf92311deedfbe1a5e77dd209468a2d7d /fpga/usrp2/control_lib/newfifo/ll8_to_fifo19.v
parentf1838b9284a124fcfb5996eaf1647a69b4473278 (diff)
parent067491b58676cbdaa754334949a8ffc2daf32979 (diff)
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Merge branch 'master' of git@ettus.sourcerepo.com:ettus/uhdpriv into usrp_e
Conflicts: .gitignore
Diffstat (limited to 'fpga/usrp2/control_lib/newfifo/ll8_to_fifo19.v')
-rw-r--r--fpga/usrp2/control_lib/newfifo/ll8_to_fifo19.v73
1 files changed, 73 insertions, 0 deletions
diff --git a/fpga/usrp2/control_lib/newfifo/ll8_to_fifo19.v b/fpga/usrp2/control_lib/newfifo/ll8_to_fifo19.v
new file mode 100644
index 000000000..af3b91afb
--- /dev/null
+++ b/fpga/usrp2/control_lib/newfifo/ll8_to_fifo19.v
@@ -0,0 +1,73 @@
+
+module ll8_to_fifo19
+ (input clk, input reset, input clear,
+ input [7:0] ll_data,
+ input ll_sof_n,
+ input ll_eof_n,
+ input ll_src_rdy_n,
+ output ll_dst_rdy_n,
+
+ output [18:0] f19_data,
+ output f19_src_rdy_o,
+ input f19_dst_rdy_i );
+
+ localparam XFER_EMPTY = 0;
+ localparam XFER_HALF = 1;
+ localparam XFER_HALF_WRITE = 3;
+
+ // Why anybody would use active low in an FPGA is beyond me...
+ wire ll_sof = ~ll_sof_n;
+ wire ll_eof = ~ll_eof_n;
+ wire ll_src_rdy = ~ll_src_rdy_n;
+ wire ll_dst_rdy;
+ assign ll_dst_rdy_n = ~ll_dst_rdy;
+
+ wire xfer_out = f19_src_rdy_o & f19_dst_rdy_i;
+ wire xfer_in = ll_src_rdy & ll_dst_rdy;
+
+ reg hold_sof;
+ wire f19_sof, f19_eof, f19_occ;
+
+ reg [1:0] state;
+ reg [7:0] hold_reg;
+
+ always @(posedge clk)
+ if(ll_src_rdy & (state==XFER_EMPTY))
+ hold_reg <= ll_data;
+
+ always @(posedge clk)
+ if(ll_sof & (state==XFER_EMPTY))
+ hold_sof <= 1;
+ else if(xfer_out)
+ hold_sof <= 0;
+
+ always @(posedge clk)
+ if(reset | clear)
+ state <= XFER_EMPTY;
+ else
+ case(state)
+ XFER_EMPTY :
+ if(ll_src_rdy)
+ if(ll_eof)
+ state <= XFER_HALF_WRITE;
+ else
+ state <= XFER_HALF;
+ XFER_HALF :
+ if(ll_src_rdy & f19_dst_rdy_i)
+ state <= XFER_EMPTY;
+ XFER_HALF_WRITE :
+ if(f19_dst_rdy_i)
+ state <= XFER_EMPTY;
+ endcase // case (state)
+
+ assign ll_dst_rdy = (state==XFER_EMPTY) | ((state==XFER_HALF)&f19_dst_rdy_i);
+ assign f19_src_rdy_o = (state==XFER_HALF_WRITE) | ((state==XFER_HALF)&ll_src_rdy);
+
+ assign f19_sof = hold_sof | (ll_sof & (state==XFER_HALF));
+ assign f19_eof = (state == XFER_HALF_WRITE) | ll_eof;
+ assign f19_occ = (state == XFER_HALF_WRITE);
+
+ assign f19_data = {f19_occ,f19_eof,f19_sof,hold_reg,ll_data};
+
+endmodule // ll8_to_fifo19
+