diff options
| -rw-r--r-- | usrp2/udp/ethtx_realign.v | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/usrp2/udp/ethtx_realign.v b/usrp2/udp/ethtx_realign.v new file mode 100644 index 000000000..74a1ef46b --- /dev/null +++ b/usrp2/udp/ethtx_realign.v @@ -0,0 +1,75 @@ + +// NOTE: Will not work with single-line frames + +module ethtx_realign + (input clk, input reset, input clear, + input [35:0] datain, input src_rdy_i, output dst_rdy_o, + output [35:0] dataout, output src_rdy_o, input dst_rdy_i); + + reg [1:0] state; + reg [15:0] held; + reg [1:0] held_occ; + reg held_sof; + + wire xfer_in = src_rdy_i & dst_rdy_o; + wire xfer_out = src_rdy_o & dst_rdy_i; + + wire sof_in = datain[32]; + wire eof_in = datain[33]; + wire [1:0] occ_in = datain[35:34]; + wire sof_out, eof_out; + wire [1:0] occ_out; + + always @(posedge clk) + if(reset | clear) + begin + held <= 0; + held_occ <= 0; + held_sof <= 0; + end + else if(xfer_in) + begin + held <= datain[15:0]; + held_occ <= datain[35:34]; + held_sof <= datain[32]; + end + + localparam RE_IDLE = 0; + localparam RE_HELD = 1; + localparam RE_DONE = 2; + + always @(posedge clk) + if(reset | clear) + state <= RE_IDLE; + else + case(state) + RE_IDLE : + if(src_rdy_i & dst_rdy_i) + if(eof_in) + state <= RE_DONE; + else + state <= RE_HELD; + + RE_HELD : + if(src_rdy_i & dst_rdy_i & eof_in) + if((occ_in==0)|(occ_in==3)) + state <= RE_DONE; + else + state <= RE_IDLE; + + RE_DONE : + if(dst_rdy_i) + state <= RE_IDLE; + + endcase // case (state) + + + assign sof_out = held_sof; + assign eof_out = (state == RE_DONE) | (occ_in == 1) | (occ_in == 2); + assign occ_out = (state == RE_DONE) ? ((held_occ == 3) ? 1 : 2) : + (occ_in == 1) ? 3 : 0; + + assign dataout = {occ_out,eof_out,sof_out,held,datain[31:16]}; + assign src_rdy_o = (state == RE_DONE) | ((state == RE_HELD) & src_rdy_i); + assign dst_rdy_o = dst_rdy_i & ((state == RE_IDLE)|(state == RE_HELD)); +endmodule // ethtx_realign |