reorganize and add support for multiple testbenches

.vscode/extensions.json

@@ -0,0 +1,8 @@
+{
+    "recommendations": [
+        "eamodio.gitlens",
+        "mhutchie.git-graph",
+        "mshr-h.veriloghdl",
+        "YuTengjing.open-in-external-app"
+    ]
+}

.vscode/settings.json

@@ -0,0 +1,24 @@
+{
+    "verilog.linting.linter": "iverilog",
+    "verilog.linting.iverilog.arguments": "-g2012 -Wall -Y .sv -i",
+    "openInExternalApp.openMapper": [
+        {
+            "extensionName": "gtkw",
+            "apps": [
+                {
+                    "title": "gtkwave",
+                    "openCommand": "gtkwave"
+                },
+            ]
+        },
+        {
+            "extensionName": "vcd",
+            "apps": [
+                {
+                    "title": "gtkwave",
+                    "openCommand": "gtkwave"
+                },
+            ]
+        }
+    ],
+}

Makefile

@@ -1,17 +1,23 @@
 PROJ = top
 DEVICE = hx8k
 PACKAGE = ct256
+# Synthesis outputs go here. Testbench outputs go with their testbenches
 BUILD_DIR = build
 PIN_DEF = constraints/pins.pcf
-SOURCE_V = $(wildcard hdl/*.v)
+# NOTE: this should work fine with .sv files too
-TESTBENCH_V = $(wildcard hdl/tb/*.v)
+# Synthesis files
+SOURCE_V = $(wildcard rtl/*.v)
+# Testbench files
+TB_V = $(wildcard tb/**/tb_*.v)
+# Testbench resources shared by all testbenches
+TB_COMMON_V = $(wildcard tb/common/*.v)
+
+TB_VCD = $(patsubst %.sv,%.vcd,$(TB_V:.v=.vcd))
 
 all: $(BUILD_DIR)/$(PROJ).rpt $(BUILD_DIR)/$(PROJ).bin
 
-$(BUILD_DIR):
+$(BUILD_DIR)/%.blif: rtl/%.v
 	mkdir -p $(BUILD_DIR)
-
-$(BUILD_DIR)/%.blif: hdl/%.v | $(BUILD_DIR)
 	yosys -p 'synth_ice40 -top top -blif $@' $(SOURCE_V)
 	# yosys -p 'synth_ice40 -top top -blif $@' $<
 
@@ -24,6 +30,13 @@ $(BUILD_DIR)/%.blif: hdl/%.v | $(BUILD_DIR)
 %.rpt: %.asc
 	icetime -d $(DEVICE) -mtr $@ $<
 
+# Simulation files
+%.out: %.v $(SOURCE_V) $(TB_COMMON_V)
+	iverilog $^ -o $@
+
+%.vcd: %.out
+	cd $(dir $@) && $(abspath $^)
+
 prog: $(PROJ).bin
 	iceprog $<
 
@@ -31,14 +44,10 @@ sudo-prog: $(PROJ).bin
 	@echo 'Executing prog as root!!!'
 	sudo iceprog $<
 
-$(BUILD_DIR)/tb.out: $(SOURCE_V) $(TESTBENCH_V) | $(BUILD_DIR)
+tb: $(TB_VCD)
-	iverilog $^ -o $@
-
-sim: $(BUILD_DIR)/tb.out
-	cd $(BUILD_DIR) && ./tb.out
 
 clean:
-	rm -rf $(BUILD_DIR)
+	rm -rf $(BUILD_DIR) $(TB_VCD) $(TB_VCD:.vcd=.out)
 
 .SECONDARY:
-.PHONY: all prog clean sim
+.PHONY: all prog clean tb

README.md

@@ -2,5 +2,10 @@
 
 Example project using Lattice ICE40 parts and [icestorm](http://www.clifford.at/icestorm/) toolchain.
 
-On Ubuntu 18.04.5 LTS, the build dependencies can be installed with:  
+On Ubuntu 22.04.1 LTS, the build dependencies can be installed with:  
-`sudo apt install iverilog yosys verilator gtkwave`
+`sudo apt install iverilog yosys verilator gtkwave arachne-pnr`
+
+
+## Viewing waveforms
+
+`.gtkw` files use absolute paths for locating the associated `.vcd` file. Manually edit the paths in `.gtkw` files if project was cloned to a new location.

tb/.gitignore

@@ -0,0 +1,2 @@
+**/*.out
+**/*.vcd

tb/top/tb_top.gtkw

@@ -2,10 +2,10 @@
 [*] GTKWave Analyzer v3.3.86 (w)1999-2017 BSI
 [*] Fri Jul  2 07:11:25 2021
 [*]
-[dumpfile] "/home/brendan/Documents/Projects/0042_ice40/build/tb.vcd"
+[dumpfile] "/home/brendan/Documents/projects/ice40/tb/top/tb_top.vcd"
 [dumpfile_mtime] "Fri Jul  2 07:10:41 2021"
 [dumpfile_size] 14906
-[savefile] "/home/brendan/Documents/Projects/0042_ice40/hdl/tb/tb.gtkw"
+[savefile] "/home/brendan/Documents/projects/ice40/tb/top/tb_top.gtkw"
 [timestart] 0
 [size] 1920 1052
 [pos] -29 -29
@@ -15,9 +15,9 @@
 [sst_expanded] 1
 [sst_vpaned_height] 311
 @28
-tb.clk
+tb_top.clk
-tb.reset
+tb_top.reset
 @8023
-tb.led[7:0]
+tb_top.led[7:0]
 [pattern_trace] 1
 [pattern_trace] 0

tb/top/tb_top.v

@@ -3,12 +3,12 @@
 
 `timescale 1ns/1ps
 
-module tb();
+module tb_top();
 
 reg clk, reset;
 wire [7:0] led;
 
-top top(
+top dut(
     .clk(clk),
     .n_reset(~reset),
     .led(led)
@@ -17,8 +17,8 @@ top top(
 always #5 clk = ~clk;
 
 initial begin
-    $dumpfile("tb.vcd");
+    $dumpfile("tb_top.vcd");
-    $dumpvars(0, tb);
+    $dumpvars(0, tb_top);
 
     clk = 0;
     reset = 1;