diff options
| -rw-r--r-- | usrp2/fifo/fifo36_mux.v | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/usrp2/fifo/fifo36_mux.v b/usrp2/fifo/fifo36_mux.v new file mode 100644 index 000000000..04ec5abe8 --- /dev/null +++ b/usrp2/fifo/fifo36_mux.v @@ -0,0 +1,57 @@ + +// Mux packets from multiple FIFO interfaces onto a single one. +// Can alternate or give priority to one port (port 0) +// In prio mode, port 1 will never get access if port 0 is always busy + +module fifo36_mux + #(parameter prio = 0) + (input clk, input reset, input clear, + input [35:0] data0_i, input src0_rdy_i, output dst0_rdy_o, + input [35:0] data1_i, input src1_rdy_i, output dst1_rdy_o, + output [35:0] data_o, output src_rdy_o, input dst_rdy_i); + + localparam MUX_IDLE0 = 0; + localparam MUX_DATA0 = 1; + localparam MUX_IDLE1 = 2; + localparam MUX_DATA1 = 3; + + reg [1:0] state; + + wire eof0 = data0_i[33]; + wire eof1 = data1_i[33]; + + always @(posedge clk) + if(reset | clear) + state <= MUX_IDLE0; + else + case(state) + MUX_IDLE0 : + if(src0_rdy_i) + state <= MUX_DATA0; + else if(src1_rdy_i) + state <= MUX_DATA1; + + MUX_DATA0 : + if(src0_rdy_i & dst_rdy_i & eof0) + state <= prio ? MUX_IDLE0 : MUX_IDLE1; + + MUX_IDLE1 : + if(src1_rdy_i) + state <= MUX_DATA1; + else if(src0_rdy_i) + state <= MUX_DATA0; + + MUX_DATA1 : + if(src1_rdy_i & dst_rdy_i & 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_0 = (state==MUX_DATA0) ? data0_i : data1_i; + +endmodule // fifo36_demux |