git.gag.com Git - debian/gnuradio/blob - usrp2/fpga/simple_gemac/rxmac_to_ll8.v

   1
   2 module rxmac_to_ll8
   3   (input clk, input reset, input clear,
   4    input [7:0] rx_data, input rx_valid, input rx_error, input rx_ack,
   5    output [7:0] ll_data, output ll_sof, output ll_eof, output ll_error, output ll_src_rdy, input ll_dst_rdy );
   6
   7    reg [2:0] xfer_state;
   8
   9    assign ll_data           = rx_data;
  10    assign ll_src_rdy        = ((rx_valid & (xfer_state != XFER_OVERRUN2) )
  11                                | (xfer_state == XFER_ERROR)
  12                                | (xfer_state == XFER_OVERRUN));
  13    assign ll_sof            = ((xfer_state==XFER_IDLE)|(xfer_state==XFER_ERROR)|(xfer_state==XFER_OVERRUN));
  14    assign ll_eof            = (rx_ack | (xfer_state==XFER_ERROR) | (xfer_state==XFER_OVERRUN));
  15    assign ll_error          = (xfer_state == XFER_ERROR)|(xfer_state==XFER_OVERRUN);
  16
  17    localparam XFER_IDLE     = 0;
  18    localparam XFER_ACTIVE   = 1;
  19    localparam XFER_ERROR    = 2;
  20    localparam XFER_ERROR2   = 3;
  21    localparam XFER_OVERRUN  = 4;
  22    localparam XFER_OVERRUN2 = 5;
  23
  24    always @(posedge clk)
  25      if(reset | clear)
  26        xfer_state          <= XFER_IDLE;
  27      else
  28        case(xfer_state)
  29          XFER_IDLE :
  30            if(rx_valid)
  31              xfer_state <= XFER_ACTIVE;
  32          XFER_ACTIVE :
  33            if(rx_error)
  34              xfer_state <= XFER_ERROR;
  35            else if(~rx_valid)
  36              xfer_state <= XFER_IDLE;
  37            else if(~ll_dst_rdy)
  38              xfer_state <= XFER_OVERRUN;
  39          XFER_ERROR :
  40            if(ll_dst_rdy)
  41              xfer_state <= XFER_ERROR2;
  42          XFER_ERROR2 :
  43            if(~rx_error)
  44              xfer_state <= XFER_IDLE;
  45          XFER_OVERRUN :
  46            if(ll_dst_rdy)
  47              xfer_state <= XFER_OVERRUN2;
  48          XFER_OVERRUN2 :
  49            if(~rx_valid)
  50              xfer_state <= XFER_IDLE;
  51        endcase // case (xfer_state)
  52
  53
  54 endmodule // rxmac_to_ll8