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fpga: lib: Add xge features for new xport_sv

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- Made some things optional to reduce logic when
   used with the new xport_sv:
   (1) Clocking to sys_clk
   (2) Preamble insertion
 - New options to CUTTHROUGH faster on the TX path.
   The new xport_sv already has a gate to accumulate at
   its clock crossing.


Original-commit: a68e7101167a4b5bf7b60ed90d963982aae735b8
This commit is contained in:
Andrew Moch
2020-07-31 13:32:59 -05:00
committed by Wade Fife
parent d5bbce58cb
commit 439c2af5e2
1 changed files with 189 additions and 98 deletions
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lib/xge_interface/xge_mac_wrapper.v
+106 -15
View File
@@ -1,6 +1,6 @@
/////////////////////////////////////////////////////////////////////
//
// Copyright 2013-2016 Ettus Research, A National Instruments Company
// Copyright 2013-2020 Ettus Research, A National Instruments Company
//
// SPDX-License-Identifier: LGPL-3.0-or-later
//
@@ -16,11 +16,20 @@
// *) On TX, to not start an Ethernet Tx until a complete packet is present in the
// last Tx FIFO so that the MAC doesn't underrun.
//
// Parameters:
// - PORTNUM: Refers to which ethernet port is being built. Added to padding but not used
// - WISHBONE: If set use wishbone implementation
// - ADD_PREAMBLE: If set add/remove 6 byte padding used in old ethernet_interface
// - CROSS_TO_SYSCLK: If set cross AXI streams to the sys_clk domain.
// - CUT_THROUGH: If > 0, how many words to wait before starting to transmit.
/////////////////////////////////////////////////////////////////////
module xge_mac_wrapper #(
parameter PORTNUM = 8'd0,
parameter WISHBONE = 1
parameter WISHBONE = 1,
parameter ADD_PREAMBLE = 1,
parameter CROSS_TO_SYSCLK = 1,
parameter CUT_THROUGH = 0
)(
// XGMII
input xgmii_clk,
@@ -83,20 +92,22 @@ module xge_mac_wrapper #(
.clk(xgmii_clk), .rst(1'b0 /* no reset */), .in(phy_ready), .out(phy_ready_xgmiiclk)
);
if (CROSS_TO_SYSCLK) begin : reset_cross
synchronizer #(
.INITIAL_VAL(1'b1), .STAGES(3)
) sys_rst_sync_i (
.clk(xgmii_clk), .rst(1'b0 /* no reset */), .in(sys_rst), .out(sys_rst_xgmiiclk)
);
assign xgmii_reset = !phy_ready_xgmiiclk || sys_rst_xgmiiclk;
end else begin : reset_no_cross
assign xgmii_reset = !phy_ready_xgmiiclk;
end
synchronizer #(
.INITIAL_VAL(1'b1), .STAGES(3)
) tx_enabled_sync_i (
.clk(xgmii_clk), .rst(1'b0 /* no reset */), .in(ctrl_tx_enable), .out(ctrl_tx_enable_xclk)
);
assign xgmii_reset = !phy_ready_xgmiiclk || sys_rst_xgmiiclk;
//
// 10G MAC
//
@@ -116,7 +127,7 @@ module xge_mac_wrapper #(
wire eth_tx_sof;
wire eth_tx_valid;
generate if (WISHBONE == 1) begin
generate if (WISHBONE == 1) begin : wishbone_mac
xge_mac_wb xge_mac_wb (
// Clocks and Resets
.clk_156m25 (xgmii_clk),
@@ -175,7 +186,7 @@ module xge_mac_wrapper #(
assign status_local_fault = 1'b0;
assign status_remote_fault = 1'b0;
end else begin
end else begin : xge_mac
xge_mac xge_mac (
// Clocks and Resets
.clk_156m25 (xgmii_clk),
@@ -246,9 +257,11 @@ module xge_mac_wrapper #(
.pkt_rx_eop(eth_rx_eof)
);
if (ADD_PREAMBLE) begin : rx_preamble
//
// Add pad of 6 empty bytes before MAC addresses of new Rxed packet so that IP
// headers are alligned. Also put metadata in first octet of pad that shows
// headers are aligned. Also put metadata in first octet of pad that shows
// ingress port.
//
xge64_to_axi64 #(
@@ -269,7 +282,17 @@ module xge_mac_wrapper #(
.axis_tvalid(rx_tvalid_int),
.axis_tready(rx_tready_int)
);
end else begin : rx_no_preamble
assign rx_tdata_int = eth_rx_data;
assign rx_tuser_int[3] = eth_rx_err;
assign rx_tuser_int[2:0] = eth_rx_occ;
assign rx_tlast_int = eth_rx_eof;
assign rx_tvalid_int = eth_rx_valid;
// there is no holdoff so ignore rx_tready_int
end
if (CROSS_TO_SYSCLK) begin : rx_cross
//
// Large FIFO must be able to run input side at 64b@156MHz to sustain 10Gb Rx.
//
@@ -291,7 +314,13 @@ module xge_mac_wrapper #(
.m_axis_tuser(rx_tuser),
.axis_rd_data_count()
);
end else begin : rx_no_cross
assign rx_tdata = rx_tdata_int;
assign rx_tuser = rx_tuser_int;
assign rx_tlast = rx_tlast_int;
assign rx_tvalid = rx_tvalid_int;
assign rx_tready_int = rx_tready;
end
///////////////////////////////////////////////////////////////////////////////////////
// TX FIFO Chain
@@ -314,6 +343,7 @@ module xge_mac_wrapper #(
wire tx_sof_int3;
wire enable_tx;
if (CROSS_TO_SYSCLK) begin : tx_cross
axi64_4k_2clk_fifo txfifo_2clk_1x (
.s_aresetn(~xgmii_reset),
.s_aclk(sys_clk),
@@ -332,7 +362,16 @@ module xge_mac_wrapper #(
.m_axis_tuser(tx_tuser_int),
.axis_rd_data_count()
);
end else begin : tx_no_cross
assign tx_tdata_int = tx_tdata;
assign tx_tuser_int = tx_tuser;
assign tx_tlast_int = tx_tlast;
assign tx_tvalid_int = tx_tvalid;
assign tx_tready = tx_tready_int;
end
if (ADD_PREAMBLE) begin : tx_preamble
//
// Strip the 6 octet ethernet padding we used internally.
// Put SOF into bit[3] of tuser.
@@ -352,11 +391,34 @@ module xge_mac_wrapper #(
.m_axis_tvalid(tx_tvalid_int2),
.m_axis_tready(tx_tready_int2)
);
end else begin : tx_no_preamble
reg sof = 1'b1;
// Add SOF
always @(posedge xgmii_clk) begin : add_sof
if (xgmii_reset) begin
sof <= 1'b1;
end else if (tx_tvalid_int && tx_tready_int) begin
sof <= tx_tlast_int;
end
end
assign tx_tdata_int2 = tx_tdata_int;
assign tx_tuser_int2[3] = sof && tx_tvalid_int;
assign tx_tuser_int2[2:0] = tx_tuser_int[2:0];
assign tx_tlast_int2 = tx_tlast_int;
assign tx_tvalid_int2 = tx_tvalid_int;
assign tx_tready_int = tx_tready_int2;
end
//
// Large FIFO can hold a max sized ethernet packet.
//
axi_fifo #(.WIDTH(64+4+1), .SIZE(10)) txfifo_2 (
wire [15:0] tx_occupied;
localparam TX_FIFO_SIZE = CUT_THROUGH > 0 ? $clog2(CUT_THROUGH)+1 : 10;
axi_fifo #(.WIDTH(64+4+1), .SIZE(TX_FIFO_SIZE)) txfifo (
.clk(xgmii_clk), .reset(xgmii_reset), .clear(1'b0),
.i_tdata({tx_tlast_int2, tx_tuser_int2, tx_tdata_int2}),
.i_tvalid(tx_tvalid_int2),
@@ -364,9 +426,38 @@ module xge_mac_wrapper #(
.o_tvalid(tx_tvalid_int3),
.o_tready(tx_tready_int3),
.o_tdata({eth_tx_eof,tx_sof_int3,eth_tx_occ,eth_tx_data}),
.space(), .occupied()
.space(), .occupied(tx_occupied)
);
//
// add cut through if we have "enough" data buffered up
//
reg cut_through;
if (CUT_THROUGH > 0) begin : yes_cut_through
wire cut_start;
wire cut_end;
assign cut_start = tx_occupied > CUT_THROUGH;
assign cut_end = eth_tx_eof && eth_tx_valid;
// Add SOF
always @(posedge xgmii_clk) begin : cut_through_dff
if (xgmii_reset) begin
cut_through <= 1'b0;
end else begin
if (cut_start) begin
cut_through <= 1'b1;
end else if (cut_end) begin
cut_through <= 1'b0;
end
end
end
end else begin : no_cut_through
always @(*) cut_through <= 0;
end
//
// Monitor number of Ethernet packets in tx_fifo2
//
@@ -385,10 +476,10 @@ module xge_mac_wrapper #(
//
//
// Supress FIFO flags to stop overflow of MAC in Tx direction
// Suppress FIFO flags to stop overflow of MAC in Tx direction
//
assign eth_tx_valid = tx_tvalid_int3 & enable_tx;
assign tx_tready_int3 = enable_tx;
assign eth_tx_sof = tx_sof_int3 & enable_tx;
assign tx_tready_int3 = (enable_tx || cut_through);
assign eth_tx_valid = (enable_tx || cut_through) & tx_tvalid_int3;
assign eth_tx_sof = (enable_tx || cut_through) & tx_sof_int3;
endmodule