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-rw-r--r--fpga/usrp2/fifo/fifo18_to_fifo36.v20
-rw-r--r--fpga/usrp2/fifo/fifo36_mux.v19
-rw-r--r--fpga/usrp2/fifo/fifo_2clock_cascade.v14
3 files changed, 43 insertions, 10 deletions
diff --git a/fpga/usrp2/fifo/fifo18_to_fifo36.v b/fpga/usrp2/fifo/fifo18_to_fifo36.v
new file mode 100644
index 000000000..25bb215a1
--- /dev/null
+++ b/fpga/usrp2/fifo/fifo18_to_fifo36.v
@@ -0,0 +1,20 @@
+
+// For now just assume FIFO18 is same as FIFO19 without occupancy bit
+
+module fifo18_to_fifo36
+ (input clk, input reset, input clear,
+ input [17:0] f18_datain,
+ input f18_src_rdy_i,
+ output f18_dst_rdy_o,
+
+ output [35:0] f36_dataout,
+ output f36_src_rdy_o,
+ input f36_dst_rdy_i
+ );
+
+ fifo19_to_fifo36 fifo19_to_fifo36
+ (.clk(clk), .reset(reset), .clear(clear),
+ .f19_datain({1'b0,f18_datain}), .f19_src_rdy_i(f18_src_rdy_i), .f19_dst_rdy_o(f18_dst_rdy_o),
+ .f36_dataout(f36_dataout), .f36_src_rdy_o(f36_src_rdy_o), .f36_dst_rdy_i(f36_dst_rdy_i) );
+
+endmodule // fifo18_to_fifo36
diff --git a/fpga/usrp2/fifo/fifo36_mux.v b/fpga/usrp2/fifo/fifo36_mux.v
index 92bf13ff9..c6fd40f27 100644
--- a/fpga/usrp2/fifo/fifo36_mux.v
+++ b/fpga/usrp2/fifo/fifo36_mux.v
@@ -20,6 +20,9 @@ module fifo36_mux
wire eof0 = data0_i[33];
wire eof1 = data1_i[33];
+ wire [35:0] data_int;
+ wire src_rdy_int, dst_rdy_int;
+
always @(posedge clk)
if(reset | clear)
state <= MUX_IDLE0;
@@ -32,7 +35,7 @@ module fifo36_mux
state <= MUX_DATA1;
MUX_DATA0 :
- if(src0_rdy_i & dst_rdy_i & eof0)
+ if(src0_rdy_i & dst_rdy_int & eof0)
state <= prio ? MUX_IDLE0 : MUX_IDLE1;
MUX_IDLE1 :
@@ -42,16 +45,20 @@ module fifo36_mux
state <= MUX_DATA0;
MUX_DATA1 :
- if(src1_rdy_i & dst_rdy_i & eof1)
+ if(src1_rdy_i & dst_rdy_int & eof1)
state <= MUX_IDLE0;
default :
state <= MUX_IDLE0;
endcase // case (state)
- assign dst0_rdy_o = (state==MUX_DATA0) ? dst_rdy_i : 0;
- assign dst1_rdy_o = (state==MUX_DATA1) ? dst_rdy_i : 0;
- assign src_rdy_o = (state==MUX_DATA0) ? src0_rdy_i : (state==MUX_DATA1) ? src1_rdy_i : 0;
- assign data_o = (state==MUX_DATA0) ? data0_i : data1_i;
+ assign dst0_rdy_o = (state==MUX_DATA0) ? dst_rdy_int : 0;
+ assign dst1_rdy_o = (state==MUX_DATA1) ? dst_rdy_int : 0;
+ assign src_rdy_int = (state==MUX_DATA0) ? src0_rdy_i : (state==MUX_DATA1) ? src1_rdy_i : 0;
+ assign data_int = (state==MUX_DATA0) ? data0_i : data1_i;
+ fifo_short #(.WIDTH(36)) mux_fifo
+ (.clk(clk), .reset(reset), .clear(clear),
+ .datain(data_int), .src_rdy_i(src_rdy_int), .dst_rdy_o(dst_rdy_int),
+ .dataout(data_o), .src_rdy_o(src_rdy_o), .dst_rdy_i(dst_rdy_i));
endmodule // fifo36_demux
diff --git a/fpga/usrp2/fifo/fifo_2clock_cascade.v b/fpga/usrp2/fifo/fifo_2clock_cascade.v
index 5ce726977..4e8c244c2 100644
--- a/fpga/usrp2/fifo/fifo_2clock_cascade.v
+++ b/fpga/usrp2/fifo/fifo_2clock_cascade.v
@@ -1,8 +1,10 @@
module fifo_2clock_cascade
#(parameter WIDTH=32, SIZE=9)
- (input wclk, input [WIDTH-1:0] datain, input src_rdy_i, output dst_rdy_o, output [15:0] space,
- input rclk, output [WIDTH-1:0] dataout, output src_rdy_o, input dst_rdy_i, output [15:0] occupied,
+ (input wclk, input [WIDTH-1:0] datain, input src_rdy_i, output dst_rdy_o,
+ output [15:0] space, output [15:0] short_space,
+ input rclk, output [WIDTH-1:0] dataout, output src_rdy_o, input dst_rdy_i,
+ output [15:0] occupied, output [15:0] short_occupied,
input arst);
wire [WIDTH-1:0] data_int1, data_int2;
@@ -29,7 +31,11 @@ module fifo_2clock_cascade
.space(s2_space), .occupied(s2_occupied));
// Be conservative -- Only advertise space from input side of fifo, occupied from output side
- assign space = {11'b0,s1_space} + l_space;
- assign occupied = {11'b0,s2_occupied} + l_occupied;
+ assign space = {11'b0,s1_space} + l_space;
+ assign occupied = {11'b0,s2_occupied} + l_occupied;
+
+ // For the fifo_extram, we only want to know the immediately adjacent space
+ assign short_space = {11'b0,s1_space};
+ assign short_occupied = {11'b0,s2_occupied};
endmodule // fifo_2clock_cascade