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authorjcorgan <jcorgan@221aa14e-8319-0410-a670-987f0aec2ac5>2008-09-08 01:00:12 +0000
committerjcorgan <jcorgan@221aa14e-8319-0410-a670-987f0aec2ac5>2008-09-08 01:00:12 +0000
commit61f2f0214c5999ea42a368a4fc99f03d8eb28d1e (patch)
treee7e24a9adc05ff1422fe3ada9926a51634741b47 /serdes/serdes_tx.v
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Merged r9433:9527 from features/gr-usrp2 into trunk. Adds usrp2 and gr-usrp2 top-level components. Trunk passes distcheck with mb-gcc installed, but currently not without them. The key issue is that when mb-gcc is not installed, the build system skips over the usrp2/firmware directory, and the firmware include files don't get put into the dist tarball. But we can't do the usual DIST_SUBDIRS method as the firmware is a subpackage.
git-svn-id: http://gnuradio.org/svn/gnuradio/trunk@9528 221aa14e-8319-0410-a670-987f0aec2ac5
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+
+// SERDES Interface
+
+// LS-Byte is sent first, MS-Byte is second
+// Invalid K Codes
+// K0.0 000-00000 Error detected
+// K31.7 111-11111 Loss of input signal
+
+// Valid K Codes
+// K28.0 000-11100
+// K28.1 001-11100 Alternate COMMA?
+// K28.2 010-11100
+// K28.3 011-11100
+// K28.4 100-11100
+// K28.5 101-11100 Standard COMMA?
+// K28.6 110-11100
+// K28.7 111-11100 Bad COMMA?
+// K23.7 111-10111
+// K27.7 111-11011
+// K29.7 111-11101
+// K30.7 111-11110
+
+module serdes_tx
+ #(parameter FIFOSIZE = 9)
+ (input clk,
+ input rst,
+
+ // TX HW Interface
+ output ser_tx_clk,
+ output reg [15:0] ser_t,
+ output reg ser_tklsb,
+ output reg ser_tkmsb,
+
+ // TX Stream Interface
+ input [31:0] rd_dat_i,
+ output rd_read_o,
+ output rd_done_o,
+ output rd_error_o,
+ input rd_sop_i,
+ input rd_eop_i,
+
+ // Flow control interface
+ input inhibit_tx,
+ input send_xon,
+ input send_xoff,
+ output sent,
+
+ // FIFO Levels
+ output [15:0] fifo_occupied,
+ output fifo_full,
+ output fifo_empty,
+
+ // DEBUG
+ output [31:0] debug
+ );
+
+ localparam K_COMMA = 8'b101_11100; // 0xBC K28.5
+ localparam K_IDLE = 8'b001_11100; // 0x3C K28.1
+ localparam K_PKT_START = 8'b110_11100; // 0xDC K28.6
+ localparam K_PKT_END = 8'b100_11100; // 0x9C K28.4
+ localparam K_XON = 8'b010_11100; // 0x5C K28.2
+ localparam K_XOFF = 8'b011_11100; // 0x7C K28.3
+ localparam K_LOS = 8'b111_11111; // 0xFF K31.7
+ localparam K_ERROR = 8'b000_00000; // 0x00 K00.0
+ localparam D_56 = 8'b110_00101; // 0xC5 D05.6
+ assign ser_tx_clk = clk;
+
+ localparam IDLE = 3'd0;
+ localparam RUN1 = 3'd1;
+ localparam RUN2 = 3'd2;
+ localparam DONE = 3'd3;
+ localparam SENDCRC = 3'd4;
+ localparam WAIT = 3'd5;
+
+ reg [2:0] state;
+
+ reg [15:0] CRC;
+ wire [15:0] nextCRC;
+ reg [3:0] wait_count;
+
+ // Internal FIFO, size 9 is 2K, size 10 is 4K bytes
+ wire sop_o, eop_o, write, full, read, empty;
+ wire [31:0] data_o;
+ reg xfer_active;
+
+ cascadefifo2 #(.WIDTH(34),.SIZE(FIFOSIZE)) serdes_tx_fifo
+ (.clk(clk),.rst(rst),.clear(0),
+ .datain({rd_sop_i,rd_eop_i,rd_dat_i}), .write(write), .full(full),
+ .dataout({sop_o,eop_o,data_o}), .read(read), .empty(empty),
+ .space(), .occupied(fifo_occupied) );
+ assign fifo_full = full;
+ assign fifo_empty = empty;
+
+ // Buffer interface to internal FIFO
+ always @(posedge clk)
+ if(rst)
+ xfer_active <= 0;
+ else if(rd_eop_i & ~full) // In case we can't store last line right away
+ xfer_active <= 0;
+ else if(rd_sop_i)
+ xfer_active <= 1;
+
+ assign write = xfer_active & ~full;
+
+ assign rd_read_o = write;
+ assign rd_done_o = 0; // Always take everything we're given
+ assign rd_error_o = 0; // No chance for errors anticipated
+
+
+ // FIXME Implement flow control
+
+ reg [15:0] second_word;
+ reg [33:0] pipeline;
+
+ assign read = (~send_xon & ~send_xoff & (state==RUN2)) | ((state==IDLE) & ~empty & ~sop_o);
+ assign sent = send_xon | send_xoff;
+ // 2nd half of above probably not necessary. Just in case we get junk between packets
+
+ always @(posedge clk)
+ if(rst)
+ begin
+ state <= IDLE;
+ wait_count <= 0;
+ {ser_tkmsb,ser_tklsb,ser_t} <= 18'd0;
+ //{2'b10,K_COMMA,K_COMMA};
+ // make tkmsb and tklsb different so they can go in IOFFs
+ end
+ else
+ if(send_xon)
+ {ser_tkmsb,ser_tklsb,ser_t} <= {2'b11,K_XON,K_XON};
+ else if(send_xoff)
+ {ser_tkmsb,ser_tklsb,ser_t} <= {2'b11,K_XOFF,K_XOFF};
+ else
+ case(state)
+ IDLE :
+ begin
+ if(sop_o & ~empty & ~inhibit_tx)
+ begin
+ {ser_tkmsb,ser_tklsb,ser_t} <= {2'b11,K_PKT_START,K_PKT_START};
+ state <= RUN1;
+ end
+ else
+ {ser_tkmsb,ser_tklsb,ser_t} <= {2'b10,K_COMMA,D_56};
+ end
+ RUN1 :
+ begin
+ if(empty | inhibit_tx)
+ {ser_tkmsb,ser_tklsb,ser_t} <= {2'b10,K_COMMA,D_56};
+ else
+ begin
+ {ser_tkmsb,ser_tklsb,ser_t} <= {2'b00,data_o[15:0]};
+ state <= RUN2;
+ end
+ end
+ RUN2 :
+ begin
+ {ser_tkmsb,ser_tklsb,ser_t} <= {2'b00,data_o[31:16]};
+ if(eop_o)
+ state <= DONE;
+ else
+ state <= RUN1;
+ end
+ DONE :
+ begin
+ {ser_tkmsb,ser_tklsb,ser_t} <= {2'b11,K_PKT_END,K_PKT_END};
+ state <= SENDCRC;
+ end
+ SENDCRC :
+ begin
+ {ser_tkmsb,ser_tklsb,ser_t} <= {2'b00,CRC};
+ state <= WAIT;
+ wait_count <= 4'd15;
+ end
+ WAIT :
+ begin
+ {ser_tkmsb,ser_tklsb,ser_t} <= {2'b10,K_COMMA,D_56};
+ if(wait_count == 0)
+ state <= IDLE;
+ else
+ wait_count <= wait_count - 1;
+ end
+ default
+ state <= IDLE;
+ endcase // case(state)
+
+ always @(posedge clk)
+ if(rst)
+ CRC <= 16'hFFFF;
+ else if(state == IDLE)
+ CRC <= 16'hFFFF;
+ else if( (~empty & ~inhibit_tx & (state==RUN1)) || (state==RUN2) )
+ CRC <= nextCRC;
+
+ CRC16_D16 crc_blk( (state==RUN1) ? data_o[15:0] : data_o[31:16], CRC, nextCRC);
+
+ assign debug = { 26'd0, full, empty, xfer_active, state[2:0] };
+
+endmodule // serdes_tx
+