examples: Wishbone interconnect test bench

examples/wb_intercon/Makefile

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+SOURCES=tb_intercon.v intercon.v master.v slave.v
+
+all: tb_intercon
+
+sim: tb_intercon
+	./tb_intercon
+
+cversim: $(SOURCES)
+	cver $(SOURCES)
+
+clean:
+	rm -f tb_intercon intercon.v intercon.vcd verilog.log
+
+tb_intercon: $(SOURCES)
+	iverilog -o tb_intercon $(SOURCES)
+
+intercon.v: intercon_conv.py
+	python3 intercon_conv.py > intercon.v
+
+.PHONY: clean sim cversim

examples/wb_intercon/intercon_conv.py

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+from migen.fhdl import verilog
+from migen.fhdl import structure as f
+from migen.bus import wishbone
+
+m1 = wishbone.Master("m1")
+m2 = wishbone.Master("m2")
+s1 = wishbone.Slave("s1")
+s2 = wishbone.Slave("s2")
+wishbonecon0 = wishbone.InterconnectShared(
+		[m1, m2],
+		[(0, s1), (1, s2)],
+		register=True,
+		offset=1)
+
+frag = wishbonecon0.GetFragment()
+v = verilog.Convert(frag, name="intercon", ios={m1.cyc_o, m1.stb_o, m1.we_o, m1.adr_o, m1.sel_o, m1.dat_o, m1.dat_i, m1.ack_i,
+	m2.cyc_o, m2.stb_o, m2.we_o, m2.adr_o, m2.sel_o, m2.dat_o, m2.dat_i, m2.ack_i,
+	s1.cyc_i, s1.stb_i, s1.we_i, s1.adr_i, s1.sel_i, s1.dat_i, s1.dat_o, s1.ack_o,
+	s2.cyc_i, s2.stb_i, s2.we_i, s2.adr_i, s2.sel_i, s2.dat_i, s2.dat_o, s2.ack_o})
+print(v)

examples/wb_intercon/master.v

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+/*
+ * Milkymist SoC
+ * Copyright (C) 2007, 2008, 2009, 2011 Sebastien Bourdeauducq
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 3 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+module master #(
+	parameter id = 0,
+	parameter nreads = 10,
+	parameter nwrites = 10,
+	parameter p = 4
+) (
+	input sys_clk,
+	input sys_rst,
+	
+	output reg [31:0] dat_w,
+	input [31:0] dat_r,
+	output reg [31:0] adr,
+	output reg we,
+	output reg [3:0] sel,
+	output cyc,
+	output stb,
+	input ack,
+	
+	output reg tend
+);
+
+integer rcounter;
+integer wcounter;
+reg active;
+
+assign cyc = active;
+assign stb = active;
+
+always @(posedge sys_clk) begin
+	if(sys_rst) begin
+		dat_w <= 0;
+		adr <= 0;
+		we <= 0;
+		sel <= 0;
+		active <= 0;
+		rcounter = 0;
+		wcounter = 0;
+		tend <= 0;
+	end else begin
+		if(ack) begin
+			if(~active)
+				$display("[M%d] Spurious ack", id);
+			else begin
+				if(we)
+					$display("[M%d] Ack W: %x:%x [%x]", id, adr, dat_w, sel);
+				else
+					$display("[M%d] Ack R: %x:%x [%x]", id, adr, dat_r, sel);
+			end
+			active <= 1'b0;
+		end else if(~active) begin
+			if(($random % p) == 0) begin
+				adr <= (($random % 5)<< (32-2)) + id;
+				sel <= sel + 1;
+				active <= 1'b1;
+				if(($random % 2) == 0) begin
+					/* Read */
+					we <= 1'b0;
+					rcounter = rcounter + 1;
+				end else begin
+					/* Write */
+					we <= 1'b1;
+					dat_w <= ($random << 16) + id;
+					wcounter = wcounter + 1;
+				end
+			end
+		end
+		tend <= (rcounter >= nreads) && (wcounter >= nwrites);
+	end
+end
+
+endmodule
+

examples/wb_intercon/slave.v

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+/*
+ * Milkymist SoC
+ * Copyright (C) 2007, 2008, 2009, 2011 Sebastien Bourdeauducq
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 3 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+module slave #(
+	parameter id = 0,
+	parameter p = 3
+) (
+	input sys_clk,
+	input sys_rst,
+	
+	input [31:0] dat_w,
+	output reg [31:0] dat_r,
+	input [31:0] adr,
+	input we,
+	input [3:0] sel,
+	input cyc,
+	input stb,
+	output reg ack
+);
+
+always @(posedge sys_clk) begin
+	if(sys_rst) begin
+		dat_r <= 0;
+		ack <= 0;
+	end else begin
+		if(cyc & stb & ~ack) begin
+			if(($random % p) == 0) begin
+				ack <= 1;
+				if(~we)
+					dat_r <= ($random << 16) + id;
+				if(we)
+					$display("[S%d] Ack W: %x:%x [%x]", id, adr, dat_w, sel);
+				else
+					$display("[S%d] Ack R: %x:%x [%x]", id, adr, dat_r, sel);
+			end
+		end else
+			ack <= 0;
+	end
+end
+
+endmodule

examples/wb_intercon/tb_intercon.v

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+/*
+ * Milkymist SoC
+ * Copyright (C) 2007, 2008, 2009, 2011 Sebastien Bourdeauducq
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 3 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+module tb_conbus();
+
+reg sys_rst;
+reg sys_clk;
+
+//------------------------------------------------------------------
+// Wishbone master wires
+//------------------------------------------------------------------
+wire [31:0]	wishbone_m1_adr,
+		wishbone_m2_adr;
+
+wire [31:0]	wishbone_m1_dat_r,
+		wishbone_m1_dat_w,
+		wishbone_m2_dat_r,
+		wishbone_m2_dat_w;
+
+wire [3:0]	wishbone_m1_sel,
+		wishbone_m2_sel;
+
+wire		wishbone_m1_we,
+		wishbone_m2_we;
+
+wire		wishbone_m1_cyc,
+		wishbone_m2_cyc;
+
+wire		wishbone_m1_stb,
+		wishbone_m2_stb;
+
+wire		wishbone_m1_ack,
+		wishbone_m2_ack;
+
+//------------------------------------------------------------------
+// Wishbone slave wires
+//------------------------------------------------------------------
+wire [31:0]	wishbone_s1_adr,
+		wishbone_s2_adr;
+
+wire [31:0]	wishbone_s1_dat_r,
+		wishbone_s1_dat_w,
+		wishbone_s2_dat_r,
+		wishbone_s2_dat_w;
+
+wire [3:0]	wishbone_s1_sel,
+		wishbone_s2_sel;
+
+wire		wishbone_s1_we,
+		wishbone_s2_we;
+
+wire		wishbone_s1_cyc,
+		wishbone_s2_cyc;
+
+wire		wishbone_s1_stb,
+		wishbone_s2_stb;
+
+wire		wishbone_s1_ack,
+		wishbone_s2_ack;
+
+//---------------------------------------------------------------------------
+// Wishbone switch
+//---------------------------------------------------------------------------
+intercon dut(
+	.sys_clk(sys_clk),
+	.sys_rst(sys_rst),
+
+	// Master 0
+	.wishbone_m1_dat_o(wishbone_m1_dat_w),
+	.wishbone_m1_dat_i(wishbone_m1_dat_r),
+	.wishbone_m1_adr_o(wishbone_m1_adr),
+	.wishbone_m1_we_o(wishbone_m1_we),
+	.wishbone_m1_sel_o(wishbone_m1_sel),
+	.wishbone_m1_cyc_o(wishbone_m1_cyc),
+	.wishbone_m1_stb_o(wishbone_m1_stb),
+	.wishbone_m1_ack_i(wishbone_m1_ack),
+	// Master 1
+	.wishbone_m2_dat_o(wishbone_m2_dat_w),
+	.wishbone_m2_dat_i(wishbone_m2_dat_r),
+	.wishbone_m2_adr_o(wishbone_m2_adr),
+	.wishbone_m2_we_o(wishbone_m2_we),
+	.wishbone_m2_sel_o(wishbone_m2_sel),
+	.wishbone_m2_cyc_o(wishbone_m2_cyc),
+	.wishbone_m2_stb_o(wishbone_m2_stb),
+	.wishbone_m2_ack_i(wishbone_m2_ack),
+
+	// Slave 0
+	.wishbone_s1_dat_o(wishbone_s1_dat_r),
+	.wishbone_s1_dat_i(wishbone_s1_dat_w),
+	.wishbone_s1_adr_i(wishbone_s1_adr),
+	.wishbone_s1_sel_i(wishbone_s1_sel),
+	.wishbone_s1_we_i(wishbone_s1_we),
+	.wishbone_s1_cyc_i(wishbone_s1_cyc),
+	.wishbone_s1_stb_i(wishbone_s1_stb),
+	.wishbone_s1_ack_o(wishbone_s1_ack),
+	// Slave 1
+	.wishbone_s2_dat_o(wishbone_s2_dat_r),
+	.wishbone_s2_dat_i(wishbone_s2_dat_w),
+	.wishbone_s2_adr_i(wishbone_s2_adr),
+	.wishbone_s2_sel_i(wishbone_s2_sel),
+	.wishbone_s2_we_i(wishbone_s2_we),
+	.wishbone_s2_cyc_i(wishbone_s2_cyc),
+	.wishbone_s2_stb_i(wishbone_s2_stb),
+	.wishbone_s2_ack_o(wishbone_s2_ack)
+);
+
+//---------------------------------------------------------------------------
+// Masters
+//---------------------------------------------------------------------------
+
+wire wishbone_m1_end;
+master #(
+	.id(0)
+) m0 (
+	.sys_clk(sys_clk),
+	.sys_rst(sys_rst),
+	
+	.dat_w(wishbone_m1_dat_w),
+	.dat_r(wishbone_m1_dat_r),
+	.adr(wishbone_m1_adr),
+	.we(wishbone_m1_we),
+	.sel(wishbone_m1_sel),
+	.cyc(wishbone_m1_cyc),
+	.stb(wishbone_m1_stb),
+	.ack(wishbone_m1_ack),
+	
+	.tend(wishbone_m1_end)
+);
+
+wire wishbone_m2_end;
+master #(
+	.id(1)
+) m1 (
+	.sys_clk(sys_clk),
+	.sys_rst(sys_rst),
+	
+	.dat_w(wishbone_m2_dat_w),
+	.dat_r(wishbone_m2_dat_r),
+	.adr(wishbone_m2_adr),
+	.we(wishbone_m2_we),
+	.sel(wishbone_m2_sel),
+	.cyc(wishbone_m2_cyc),
+	.stb(wishbone_m2_stb),
+	.ack(wishbone_m2_ack),
+	
+	.tend(wishbone_m2_end)
+);
+
+//---------------------------------------------------------------------------
+// Slaves
+//---------------------------------------------------------------------------
+
+slave #(
+	.id(0)
+) s0 (
+	.sys_clk(sys_clk),
+	.sys_rst(sys_rst),
+
+	.dat_w(wishbone_s1_dat_w),
+	.dat_r(wishbone_s1_dat_r),
+	.adr(wishbone_s1_adr),
+	.we(wishbone_s1_we),
+	.sel(wishbone_s1_sel),
+	.cyc(wishbone_s1_cyc),
+	.stb(wishbone_s1_stb),
+	.ack(wishbone_s1_ack)
+);
+
+slave #(
+	.id(1)
+) s1 (
+	.sys_clk(sys_clk),
+	.sys_rst(sys_rst),
+
+	.dat_w(wishbone_s2_dat_w),
+	.dat_r(wishbone_s2_dat_r),
+	.adr(wishbone_s2_adr),
+	.we(wishbone_s2_we),
+	.sel(wishbone_s2_sel),
+	.cyc(wishbone_s2_cyc),
+	.stb(wishbone_s2_stb),
+	.ack(wishbone_s2_ack)
+);
+
+initial sys_clk = 1'b0;
+always #5 sys_clk = ~sys_clk;
+
+wire all_end = wishbone_m1_end & wishbone_m2_end;
+
+always begin
+	$dumpfile("intercon.vcd");
+	$dumpvars(1, dut);
+	sys_rst = 1'b1;
+	@(posedge sys_clk);
+	#1 sys_rst = 1'b0;
+	@(posedge all_end);
+	$finish;
+end
+
+endmodule