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b210-k7-fpga/lib/gpif2/gpif2_slave_fifo32.v
T
Ben Hilburn c91b74de33 Squashed B200 FPGA Source. Code from Josh Blum, Ian Buckley, and Matt Ettus.
Original-commit: 0df4b801a34697f2058b4a7b95e08d2a0576c9db
2013-10-10 10:17:27 -07:00

376 lines
13 KiB
Verilog

//
// Copyright 2011-2013 Ettus Research LLC
//
//////////////////////////////////////////////////////////////////////////////////
//this is a FIFO master interface for the FX3 in "slave fifo" mode.
module gpif2_slave_fifo32
#(
//sizes for fifo64 2 clock cascade fifos
parameter DATA_RX_FIFO_SIZE = 12, //max vita pkt size
parameter DATA_TX_FIFO_SIZE = 12, //max vita pkt size
parameter CTRL_RX_FIFO_SIZE = 5, //small resp packets
parameter CTRL_TX_FIFO_SIZE = 5, //small ctrl packets
//address constants for the endpoints
parameter ADDR_DATA_TX = 2'b00,
parameter ADDR_DATA_RX = 2'b01,
parameter ADDR_CTRL_TX = 2'b10,
parameter ADDR_CTRL_RX = 2'b11,
parameter END_WITH_COMMA = 0
)
(// GPIF signals
input gpif_clk, input gpif_rst, input gpif_enb,
inout [31:0] gpif_d,
input [3:0] gpif_ctl,
output reg sloe,
output reg slrd,
output reg slwr,
output slcs,
output reg pktend,
output reg [1:0] fifoadr,
// FIFO interfaces
input fifo_clk, input fifo_rst,
output [63:0] tx_tdata, output tx_tlast, output tx_tvalid, input tx_tready,
input [63:0] rx_tdata, input rx_tlast, input rx_tvalid, output rx_tready,
output [63:0] ctrl_tdata, output ctrl_tlast, output ctrl_tvalid, input ctrl_tready,
input [63:0] resp_tdata, input resp_tlast, input resp_tvalid, output resp_tready,
output [31:0] debug
);
reg fifo_nearly_full;
wire ctrl_tx_fifo_nearly_full, data_tx_fifo_nearly_full;
wire ctrl_tx_fifo_has_space, data_tx_fifo_has_space;
wire [159:0] debug_tx_data, debug_tx_ctrl;
assign slcs = 1'b0;
//DMA FIFO ready and watermark flags
reg EP_READY, EP_READY1, EP_WMARK, EP_WMARK1;
always @(posedge gpif_clk) EP_READY <= gpif_ctl[0];
always @(posedge gpif_clk) EP_WMARK <= gpif_ctl[1];
always @(posedge gpif_clk) EP_READY1 <= EP_READY;
always @(posedge gpif_clk) EP_WMARK1 <= EP_WMARK;
// GPIF output data lines, tristate
reg [31:0] gpif_data_in, gpif_data_out;
always @(posedge gpif_clk) gpif_data_in <= gpif_d;
assign gpif_d = sloe ? gpif_data_out[31:0] : 32'bz;
// ////////////////////////////////////////////////////////////////////
// GPIF bus master state machine
wire wr_fifo_xfer, wr_fifo_eof;
wire [31:0] wr_fifo_data;
reg read_ready_go, write_ready_go;
reg wr_one, rd_one;
reg [3:0] state; //state machine current state
localparam STATE_IDLE = 0;
localparam STATE_THINK = 1;
localparam STATE_READ = 2;
localparam STATE_WRITE = 3;
localparam STATE_WAIT = 4;
reg [2:0] idle_cycles;
reg [1:0] last_addr, next_addr;
wire local_fifo_ready;
reg slrd1, slrd2, slrd3;
always @(posedge gpif_clk)
if (gpif_rst) begin
slrd1 <= 1;
slrd2 <= 1;
slrd3 <= 1;
end else begin
slrd1 <= slrd;
slrd2 <= slrd1;
slrd3 <= slrd2;
end
wire RD_VALID = ~slrd3;
wire RD_LAST = slrd2;
wire WR_VALID = (EP_WMARK1 || !wr_one);
// //////////////////////////////////////////////////////////////
// FX2 slave FIFO bus master state machine
//
always @(posedge gpif_clk)
if(gpif_rst) begin
state <= STATE_IDLE;
sloe <= 0;
slrd <= 1;
slwr <= 1;
pktend <= 1;
gpif_data_out <= 32'b0;
idle_cycles <= 0;
fifoadr <= 0;
wr_one <= 1'b0;
rd_one <= 1'b0;
last_addr <= 2'b0;
end
else if (gpif_enb) begin
case (state)
//
// Increment fifoadr to point at next thread, set all strobes to idle,
//
STATE_IDLE: begin
sloe <= 0;
slrd <= 1;
slwr <= 1;
pktend <= 1;
gpif_data_out <= 32'b0;
fifoadr <= next_addr;
state <= STATE_WAIT;
idle_cycles <= 0;
end
//
// now wait here for 8 clock cycles before transitioning to STATE_THINK.
// We stay in this state if no local FIFO's can proceed at this point.
//
STATE_WAIT: begin
if (local_fifo_ready) begin
idle_cycles <= idle_cycles + 1'b1;
if (idle_cycles == 3'b111) state <= STATE_THINK;
end
else begin
idle_cycles <= 3'b0;
fifoadr <= fifoadr + 2'b1;
end
end
//
// If there is a read to start, assert SLRD and SLOE and transition to STATE_READ.
// If there is a write to perform, set flags that says there is the possibility to do at least
// one write (wr_one) and transition to STATE_WRITE
//
STATE_THINK: begin
if (EP_READY1 && read_ready_go) begin
state <= STATE_READ;
slrd <= 0;
rd_one <= 0;
end
else if (EP_READY1 && write_ready_go) begin
state <= STATE_WRITE;
sloe <= 1;
wr_one <= 1'b0;
end
else begin
state <= STATE_IDLE;
end
idle_cycles <= 0;
last_addr <= fifoadr;
end
// If flag rd_one is set (armed 5 cycles after slrd goes initialy assrted) and RD_VALID has gone deasserted
// (meaning that the watermark deasserted 5 clock cycles ago) transition to STATE_IDLE.
// If watermark deasserted 2 cycles ago de-assert slrd ...read data is still traveling in the pipeline.
// Whilst RD_VALID stays asserted keep the rd_one flag armed.
STATE_READ: begin
if (rd_one && ~RD_VALID) state <= STATE_IDLE;
if (~EP_WMARK1 | fifo_nearly_full) slrd <= 1;
if (RD_VALID) rd_one <= 1'b1;
end
// If local FIFO goes empty or tlast is set then transition to STATE_IDLE
// Push local FIFO data out onto GPIF data bus.
// if local FIFO has valid data then assert slwr
// if local FIFO assertes tlast then assert pktend
// If WR_VALID asserted (because wr_one already asserted in the first cycle in this state)
// now clear wr_one (watermark will keep WR_VALID asserted from now on if this is a burst).
//
STATE_WRITE: begin
if (~wr_fifo_xfer || wr_fifo_eof) state <= STATE_IDLE;
gpif_data_out <= wr_fifo_data;
slwr <= ~wr_fifo_xfer;
pktend <= ~wr_fifo_eof;
if (WR_VALID) wr_one <= 1'b1;
end
default: state <= STATE_IDLE;
endcase
end
// ///////////////////////////////////////////////////////////////////
// fifo signal assignments and enables
//output from fifos - ready to xfer
wire data_tx_tready, ctrl_tx_tready;
wire ctrl_rx_tvalid, data_rx_tvalid;
//Priority encoding for the the next address to service:
//The next address to service is based on the readiness
//of the internal fifos and last serviced fairness metric.
always @(posedge gpif_clk) next_addr <=
((ctrl_rx_tvalid && last_addr != ADDR_CTRL_RX)? ADDR_CTRL_RX :
((ctrl_tx_fifo_has_space && last_addr != ADDR_CTRL_TX)? ADDR_CTRL_TX :
((data_rx_tvalid && last_addr != ADDR_DATA_RX)? ADDR_DATA_RX :
((data_tx_fifo_has_space && last_addr != ADDR_DATA_TX)? ADDR_DATA_TX :
(fifoadr + 2'b1)
))));
//Help the FPGA search to only look for addrs that the FPGA is ready for
assign local_fifo_ready =
(ctrl_rx_tvalid && (fifoadr == ADDR_CTRL_RX)) ||
(ctrl_tx_fifo_has_space && (fifoadr == ADDR_CTRL_TX)) ||
(data_rx_tvalid && (fifoadr == ADDR_DATA_RX)) ||
(data_tx_fifo_has_space && (fifoadr == ADDR_DATA_TX));
always @(posedge gpif_clk) fifo_nearly_full <=
(ctrl_tx_fifo_nearly_full && (fifoadr == ADDR_CTRL_TX)) ||
(data_tx_fifo_nearly_full && (fifoadr == ADDR_DATA_TX));
always @(posedge gpif_clk) read_ready_go <=
(ctrl_tx_fifo_has_space && (fifoadr == ADDR_CTRL_TX)) ||
(data_tx_fifo_has_space && (fifoadr == ADDR_DATA_TX));
always @(posedge gpif_clk) write_ready_go <=
(ctrl_rx_tvalid && (fifoadr == ADDR_CTRL_RX)) ||
(data_rx_tvalid && (fifoadr == ADDR_DATA_RX));
//fifo xfer enable
wire data_rx_tready = (state == STATE_WRITE) && (fifoadr == ADDR_DATA_RX) && WR_VALID;
wire ctrl_rx_tready = (state == STATE_WRITE) && (fifoadr == ADDR_CTRL_RX) && WR_VALID;
wire data_tx_tvalid = (state == STATE_READ) && (fifoadr == ADDR_DATA_TX) && RD_VALID;
wire ctrl_tx_tvalid = (state == STATE_READ) && (fifoadr == ADDR_CTRL_TX) && RD_VALID;
//outputs from rx fifo paths
wire ctrl_rx_tlast, data_rx_tlast;
wire [31:0] ctrl_rx_tdata, data_rx_tdata;
//mux rx outputs for gpif state machine
assign wr_fifo_xfer = (fifoadr == ADDR_CTRL_RX)? (ctrl_rx_tvalid && ctrl_rx_tready) : (data_rx_tvalid && data_rx_tready);
assign wr_fifo_eof = wr_fifo_xfer && ((fifoadr == ADDR_CTRL_RX)? ctrl_rx_tlast : data_rx_tlast);
assign wr_fifo_data = (fifoadr == ADDR_CTRL_RX)? ctrl_rx_tdata : data_rx_tdata;
wire ctrl_bus_error, tx_bus_error;
// ////////////////////////////////////////////////////////////////////
// TX Data Path
gpif2_to_fifo64 #(.FIFO_SIZE(DATA_TX_FIFO_SIZE)) gpif2_to_fifo64_tx(
.gpif_clk(gpif_clk), .gpif_rst(gpif_rst),
.i_tdata(gpif_data_in), .i_tlast(RD_LAST), .i_tvalid(data_tx_tvalid), .i_tready(data_tx_tready),
.fifo_clk(fifo_clk), .fifo_rst(fifo_rst),
.fifo_nearly_full(data_tx_fifo_nearly_full), .fifo_has_space(data_tx_fifo_has_space),
.o_tdata(tx_tdata), .o_tlast(tx_tlast), .o_tvalid(tx_tvalid), .o_tready(tx_tready),
.bus_error(tx_bus_error), .debug(debug_tx_data)
);
// ////////////////////////////////////////////
// RX Data Path
fifo64_to_gpif2 #(.FIFO_SIZE(DATA_RX_FIFO_SIZE)) fifo64_to_gpif2_rx(
.fifo_clk(fifo_clk), .fifo_rst(fifo_rst),
.i_tdata(rx_tdata), .i_tlast(rx_tlast), .i_tvalid(rx_tvalid), .i_tready(rx_tready),
.gpif_clk(gpif_clk), .gpif_rst(gpif_rst),
.o_tdata(data_rx_tdata), .o_tlast(data_rx_tlast), .o_tvalid(data_rx_tvalid), .o_tready(data_rx_tready)
);
// ////////////////////////////////////////////////////////////////////
// CTRL path
gpif2_to_fifo64 #(.FIFO_SIZE(CTRL_TX_FIFO_SIZE)) gpif2_to_fifo64_ctrl(
.gpif_clk(gpif_clk), .gpif_rst(gpif_rst),
.i_tdata(gpif_data_in), .i_tlast(RD_LAST), .i_tvalid(ctrl_tx_tvalid), .i_tready(ctrl_tx_tready),
.fifo_clk(fifo_clk), .fifo_rst(fifo_rst),
.fifo_nearly_full(ctrl_tx_fifo_nearly_full), .fifo_has_space(ctrl_tx_fifo_has_space),
.o_tdata(ctrl_tdata), .o_tlast(ctrl_tlast), .o_tvalid(ctrl_tvalid), .o_tready(ctrl_tready),
.bus_error(ctrl_bus_error), .debug(debug_tx_ctrl)
);
// ////////////////////////////////////////////////////////////////////
// RESP path
fifo64_to_gpif2 #(.FIFO_SIZE(CTRL_RX_FIFO_SIZE)) fifo64_to_gpif2_resp(
.fifo_clk(fifo_clk), .fifo_rst(fifo_rst),
.i_tdata(resp_tdata), .i_tlast(resp_tlast), .i_tvalid(resp_tvalid), .i_tready(resp_tready),
.gpif_clk(gpif_clk), .gpif_rst(gpif_rst),
.o_tdata(ctrl_rx_tdata), .o_tlast(ctrl_rx_tlast), .o_tvalid(ctrl_rx_tvalid), .o_tready(ctrl_rx_tready)
);
// ////////////////////////////////////////////
// DEBUG
wire [31:0] debug0 = {
sloe, slrd, slwr, pktend, fifoadr, EP_READY, EP_WMARK, //8
state, //4
data_tx_tvalid, data_tx_tready, data_rx_tvalid, data_rx_tready, //4
gpif_d[15:0] //16
};
reg [31:0] debug_reg0;
reg [31:0] debug_reg1;
reg [31:0] debug_reg2;
always @(posedge gpif_clk) debug_reg0 <= debug0;
always @(posedge gpif_clk) debug_reg1 <= debug_reg0;
always @(posedge gpif_clk) debug_reg2 <= debug_reg1;
assign debug = debug_reg2;
wire [37:0] debug_resp = {
resp_tlast, // 37
resp_tready, // 36
resp_tvalid, // 35
ctrl_rx_tlast, // 34
ctrl_rx_tready, // 33
ctrl_rx_tvalid, // 32
ctrl_rx_tdata // 31:0
};
reg [255:0] debug1,debug2;
always @(posedge gpif_clk) debug1 <= {debug_resp,debug_tx_ctrl,debug0};
always @(posedge gpif_clk) debug2 <= debug1;
wire [35:0] CONTROL0,CONTROL1;
/*
chipscope_ila_32 chipscope_ila_32(
.CONTROL(CONTROL0), // INOUT BUS [35:0]
.CLK(gpif_clk), // IN
.TRIG0(debug2) // IN BUS [31:0]
);
chipscope_ila_128 chipscope_ila_128(
.CONTROL(CONTROL1), // INOUT BUS [35:0]
.CLK(fifo_clk), // IN
.TRIG0({debug4,debug6}) // IN BUS [31:0]
);
chipscope_ila_256 chipscope_ila_256(
.CONTROL(CONTROL0), // INOUT BUS [35:0]
.CLK(gpif_clk), // IN
.TRIG0(debug2) // IN BUS [31:0]
);
chipscope_ila_32 chipscope_ila_32_2(
.CONTROL(CONTROL1), // INOUT BUS [35:0]
.CLK(gpif_clk), // IN
.TRIG0(32'd0) // IN BUS [31:0]
);
chipscope_icon chipscope_icon(
.CONTROL0(CONTROL0), // INOUT BUS [35:0]
.CONTROL1(CONTROL1) // INOUT BUS [35:0]
);
*/
endmodule // gpif2_slave_fifo32