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Diffstat (limited to 'inband_lib/packet_builder.v')
| -rwxr-xr-x | inband_lib/packet_builder.v | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/inband_lib/packet_builder.v b/inband_lib/packet_builder.v new file mode 100755 index 000000000..205293479 --- /dev/null +++ b/inband_lib/packet_builder.v @@ -0,0 +1,132 @@ +module packet_builder #(parameter NUM_CHAN = 1)( + // System + input rxclk, + input reset, + input [31:0] adctime, + input [3:0] channels, + // ADC side + input [15:0]chan_fifodata, + input [NUM_CHAN:0]chan_empty, + input [9:0]chan_usedw, + output reg [3:0]rd_select, + output reg chan_rdreq, + // FX2 side + output reg WR, + output reg [15:0]fifodata, + input have_space, + input wire [31:0]rssi_0, input wire [31:0]rssi_1, input wire [31:0]rssi_2, + input wire [31:0]rssi_3, output wire [7:0] debugbus); + + + // States + `define IDLE 3'd0 + `define HEADER1 3'd1 + `define HEADER2 3'd2 + `define TIMESTAMP 3'd3 + `define FORWARD 3'd4 + + `define MAXPAYLOAD 504 + + `define PAYLOAD_LEN 8:0 + `define TAG 12:9 + `define MBZ 15:13 + + `define CHAN 4:0 + `define RSSI 10:5 + `define BURST 12:11 + `define DROPPED 13 + `define UNDERRUN 14 + `define OVERRUN 15 + + reg [2:0] state; + reg [8:0] read_length; + reg [8:0] payload_len; + reg tstamp_complete; + reg [3:0] check_next; + wire [8:0] chan_used; + wire [31:0] true_rssi; + + assign debugbus = {state, chan_empty[0], chan_empty[1], check_next[0], + have_space, rd_select[0]}; + assign chan_used = chan_usedw[8:0]; + assign true_rssi = (rd_select[1]) ? ((rd_select[0]) ? rssi_3:rssi_2) : + ((rd_select[0]) ? rssi_1:rssi_0); + always @(posedge rxclk) + begin + if (reset) + begin + WR <= 0; + rd_select <= 0; + chan_rdreq <= 0; + tstamp_complete <= 0; + check_next <= 0; + state <= `IDLE; + end + else case (state) + `IDLE: begin + if (have_space) + begin + if(~chan_empty[check_next]) + begin + state <= #1 `HEADER1; + rd_select <= #1 check_next; + end + check_next <= #1 (check_next == channels ? 4'd0 : check_next + 4'd1); + end + end + + `HEADER1: begin + fifodata[`PAYLOAD_LEN] <= #1 (chan_used > 9'd252 + ? 9'd252 : chan_used << 1); + payload_len <= #1 (chan_used > 9'd252 + ? 9'd252 : chan_used << 1); + fifodata[`TAG] <= #1 0; + fifodata[`MBZ] <= #1 0; + WR <= #1 1; + + state <= #1 `HEADER2; + read_length <= #1 0; + end + + `HEADER2: begin + fifodata[`CHAN] <= #1 (check_next == 4'd0 ? 5'h1f : {1'd0, check_next - 4'd1}); + fifodata[`RSSI] <= #1 true_rssi[5:0]; + fifodata[`BURST] <= #1 0; + fifodata[`DROPPED] <= #1 0; + fifodata[`UNDERRUN] <= #1 0; + fifodata[`OVERRUN] <= #1 0; + + state <= #1 `TIMESTAMP; + end + + `TIMESTAMP: begin + fifodata <= #1 (tstamp_complete ? adctime[31:16] : adctime[15:0]); + tstamp_complete <= #1 ~tstamp_complete; + + if (~tstamp_complete) + chan_rdreq <= #1 1; + + state <= #1 (tstamp_complete ? `FORWARD : `TIMESTAMP); + end + + `FORWARD: begin + read_length <= #1 read_length + 9'd2; + fifodata <= #1 (read_length >= payload_len ? 16'hDEAD : chan_fifodata); + + if (read_length >= `MAXPAYLOAD) + begin + WR <= #1 0; + state <= #1 `IDLE; + end + else if (read_length == payload_len - 4) + chan_rdreq <= #1 0; + end + + default: begin + //handling error state + state <= `IDLE; + end + endcase + end +endmodule + |