Chisel 学习笔记 (一)

作者: 走在成长的道路上 | 来源:发表于2018-11-14 17:02 被阅读0次

尝试学习 Chisel 语言，“工欲善其事，必先利其器”，因此先扫除环境问题。

基础环境

本笔记使用的基础环境是 ubuntu 16.04 ， Idea 进行开发，在 ubuntu 中安装如下工具

名称	描述
verilator	RTL仿真平台， rocket-chip 默认仿真平台
iverilog	RTL仿真平台，执行编译，生成的文件通过vvp执行仿真
gtkwave	图形化波形显示

通过如下命令进行安装：

$ sudo apt install -y verilator iverilog gtkwave git

iVerilog 使用方法

选项	说明
-D macro[=def ]	定义宏
-I incdir	等同于-incdir
-o filename	指定输出的可执行文件名
-s topmodule	等同于-top
-y libdir	等同于-y

例如：

编写简单的模块 Adder.v

module Adder(
  input  [7:0] io_in0,
  input  [7:0] io_in1,
  output [7:0] io_out
);
  wire [8:0] _T_11;
  assign _T_11 = io_in0 + io_in1;
  assign io_out = _T_11[7:0];
endmodule

编写测试用例 AdderTester.v

module AdderTester; 

reg[7:0] in0; 
reg[7:0] in1; 
wire[7:0] out; 

initial begin 
// 从这里开始是输入参数
// 第 1 组参数
  in0 = 8'h35; 
  in1 = 8'h56; 
// 第 2 组参数
  #1  in0 = 8'h39; 
      in1 = 8'h28; 
// 第 3 组参数
  #1  in0 = 8'h10; 
      in1 = 8'h09; 
// 第 4 组参数
  #1  in0 = 8'h15; 
      in1 = 8'h20; 
// 停止测试
  #1 $stop; 
end   

// 配置 Adder 模块的引脚配置
  Adder AdderInstance( 
    .io_in0(in0), 
    .io_in1(in1), 
    .io_out(out) 
  ); 

// 打印波形文件
initial begin 
// 输出 vcd 文件，最后通过 gtkwave 文件进行显示
  $dumpfile("AdderTester.vcd"); 
  $dumpvars(0, AdderTester); 
end 

endmodule

进行仿真

$ iverilog -o test Adder.v AdderTester.v
$ vvp -n test

gtkwave 波形

通过如下命令查看 vcd 文件

$ gtkwave AdderTester.vcd

如下图所示：

波形图

开发环境

如本文初所述，使用采用 chisel 语言进行开发，使用 idea 做编辑器，使用 sbt 做依赖库管理，因此这里简单介绍下 sbt 环境安装即可。

$ wget https://dl.bintray.com/sbt/debian/sbt-0.13.11.deb
$ sudo dpkg -i sbt-0.13.11.deb

sbt 使用

创建模块 Adder.scala

import chisel3._
import chisel3.iotesters.{SteppedHWIOTester, ChiselFlatSpec}
import chisel3.testers.TesterDriver

class Adder(val w: Int) extends Module {
  val io = IO(new Bundle {
    val in0 = Input(UInt(w.W))
    val in1 = Input(UInt(w.W))
    val out = Output(UInt(w.W))
  })
  io.out := io.in0 + io.in1
}

class AdderTester extends SteppedHWIOTester {
  val device_under_test = Module( new Adder(8) )
  val c = device_under_test
  enable_all_debug = true

  rnd.setSeed(0L)
  for (i <- 0 until 3) {
    val in0 = rnd.nextInt(1 << c.w)
    val in1 = rnd.nextInt(1 << c.w)
    poke(c.io.in0, in0)
    poke(c.io.in1, in1)
    expect(c.io.out, (in0 + in1) & ((1 << c.w) - 1))

    step(1)
  }
}

object Adder {
  def main(args: Array[String]): Unit = {
    TesterDriver.execute { () => new AdderTester }
  }
}

class AdderSpec extends ChiselFlatSpec {
  "Adder" should "compile and run without incident" in {
    assertTesterPasses { new AdderTester }
  }
}

编写 build.sbt 文件

这里仿照 chisel-tutorial 项目编写即可：

version := "3.1.0"

name := "chisel-tutorial"

scalaVersion := "2.11.12"

crossScalaVersions := Seq("2.11.12", "2.12.4")

scalacOptions ++= Seq("-deprecation", "-feature", "-unchecked", "-language:reflectiveCalls")

// Provide a managed dependency on X if -DXVersion="" is supplied on the command line.
// The following are the current "release" versions.
val defaultVersions = Map(
  "chisel3" -> "3.1.+",
  "chisel-iotesters" -> "1.2.+",
  "treadle" -> "1.0.1"
  )

libraryDependencies ++= (Seq("chisel3","chisel-iotesters").map {
  dep: String => "edu.berkeley.cs" %% dep % sys.props.getOrElse(dep + "Version", defaultVersions(dep)) })

libraryDependencies ++= Seq(
  "org.scalatest" %% "scalatest" % "3.0.1" % "test"
)

resolvers ++= Seq(
  Resolver.sonatypeRepo("snapshots"),
  Resolver.sonatypeRepo("releases")
)

// Recommendations from http://www.scalatest.org/user_guide/using_scalatest_with_sbt
logBuffered in Test := true

// Disable parallel execution when running tests.
//  Running tests in parallel on Jenkins currently fails.
parallelExecution in Test := false

publishMavenStyle := true

publishArtifact in Test := true

pomIncludeRepository := { x => false }

pomExtra := (
<url>http://chisel.eecs.berkeley.edu/</url>
<licenses>
  <license>
    <name>BSD-style</name>
    <url>http://www.opensource.org/licenses/bsd-license.php</url>
    <distribution>repo</distribution>
  </license>
</licenses>
<scm>
  <url>https://github.com/ucb-bar/chisel-testers2.git</url>
  <connection>scm:git:github.com/ucb-bar/chisel-testers2.git</connection>
</scm>
)

// Recommendations from http://www.scalatest.org/user_guide/using_scalatest_with_sbt
logBuffered in Test := true

// Disable parallel execution when running tests.
//  Running tests in parallel on Jenkins currently fails.
parallelExecution in Test := false

publishMavenStyle := true

publishArtifact in Test := true

pomIncludeRepository := { x => false }

pomExtra := (
<url>http://chisel.eecs.berkeley.edu/</url>
<licenses>
  <license>
    <name>BSD-style</name>
    <url>http://www.opensource.org/licenses/bsd-license.php</url>
    <distribution>repo</distribution>
  </license>
</licenses>
<scm>
  <url>https://github.com/ucb-bar/chisel-testers2.git</url>
  <connection>scm:git:github.com/ucb-bar/chisel-testers2.git</connection>
</scm>
)

publishTo := {
  val v = version.value
  val nexus = "https://oss.sonatype.org/"
  if (v.trim.endsWith("SNAPSHOT")) {
    Some("snapshots" at nexus + "content/repositories/snapshots")
  }
  else {
    Some("releases" at nexus + "service/local/staging/deploy/maven2")
  }
}

trapExit := false

编译执行

$ sbt run

如下是其日志：

uc : /srv/workspace/chisel$ sbt clean run
[info] Set current project to chisel-tutorial (in build file:/srv/workspace/chisel/)
[success] Total time: 0 s, completed Nov 14, 2018 7:51:19 PM
[info] Updating {file:/srv/workspace/chisel/}chisel...
[info] Resolving jline#jline;2.14.3 ...
[info] Done updating.
[info] Compiling 1 Scala source to /srv/workspace/chisel/target/scala-2.11/classes...
[info] Running Adder 
[info] [0.001] Elaborating design...
================================================================================
Device under test: io bundle
  #  Dir  D/V   Used   Name                      Parent
--------------------------------------------------------------------------------
  0    I          y    in0                       
  1    I          y    in1                       
  2    O          y    out                       
================================================================================
================================================================================
UnitTester state table
  step  in1  in0  out
--------------------------------------------------------------------------------
     0  851  748  575
     1  620  246  866
     2  316  652  968
     3    -    -    -
================================================================================
[info] [0.453] Done elaborating.
Total FIRRTL Compile Time: 279.0 ms
verilator --cc /srv/workspace/chisel/test_run_dir/AdderTester/201811141951384238257037378005420/AdderTester.v --assert -Wno-fatal -Wno-WIDTH -Wno-STMTDLY --trace -O1 --top-module AdderTester +define+TOP_TYPE=VAdderTester +define+PRINTF_COND=!AdderTester.reset +define+STOP_COND=!AdderTester.reset -CFLAGS -Wno-undefined-bool-conversion -O1 -DTOP_TYPE=VAdderTester -DVL_USER_FINISH -include VAdderTester.h -Mdir /srv/workspace/chisel/test_run_dir/AdderTester/201811141951384238257037378005420 --exe /srv/workspace/chisel/test_run_dir/AdderTester/201811141951384238257037378005420/top.cpp
make: Entering directory '/srv/workspace/chisel/test_run_dir/AdderTester/201811141951384238257037378005420'
g++  -I.  -MMD -I/usr/share/verilator/include -I/usr/share/verilator/include/vltstd -DVL_PRINTF=printf -DVM_COVERAGE=0 -DVM_SC=0 -DVM_TRACE=1 -faligned-new -Wno-sign-compare -Wno-uninitialized -Wno-unused-but-set-variable -Wno-unused-parameter -Wno-unused-variable -Wno-shadow     -Wno-undefined-bool-conversion -O1 -DTOP_TYPE=VAdderTester -DVL_USER_FINISH -include VAdderTester.h   -c -o top.o /srv/workspace/chisel/test_run_dir/AdderTester/201811141951384238257037378005420/top.cpp
g++  -I.  -MMD -I/usr/share/verilator/include -I/usr/share/verilator/include/vltstd -DVL_PRINTF=printf -DVM_COVERAGE=0 -DVM_SC=0 -DVM_TRACE=1 -faligned-new -Wno-sign-compare -Wno-uninitialized -Wno-unused-but-set-variable -Wno-unused-parameter -Wno-unused-variable -Wno-shadow     -Wno-undefined-bool-conversion -O1 -DTOP_TYPE=VAdderTester -DVL_USER_FINISH -include VAdderTester.h   -c -o verilated.o /usr/share/verilator/include/verilated.cpp
g++  -I.  -MMD -I/usr/share/verilator/include -I/usr/share/verilator/include/vltstd -DVL_PRINTF=printf -DVM_COVERAGE=0 -DVM_SC=0 -DVM_TRACE=1 -faligned-new -Wno-sign-compare -Wno-uninitialized -Wno-unused-but-set-variable -Wno-unused-parameter -Wno-unused-variable -Wno-shadow     -Wno-undefined-bool-conversion -O1 -DTOP_TYPE=VAdderTester -DVL_USER_FINISH -include VAdderTester.h   -c -o verilated_vcd_c.o /usr/share/verilator/include/verilated_vcd_c.cpp
/usr/bin/perl /usr/share/verilator/bin/verilator_includer -DVL_INCLUDE_OPT=include VAdderTester.cpp > VAdderTester__ALLcls.cpp
/usr/bin/perl /usr/share/verilator/bin/verilator_includer -DVL_INCLUDE_OPT=include VAdderTester__Trace.cpp VAdderTester__Syms.cpp VAdderTester__Trace__Slow.cpp > VAdderTester__ALLsup.cpp
g++  -I.  -MMD -I/usr/share/verilator/include -I/usr/share/verilator/include/vltstd -DVL_PRINTF=printf -DVM_COVERAGE=0 -DVM_SC=0 -DVM_TRACE=1 -faligned-new -Wno-sign-compare -Wno-uninitialized -Wno-unused-but-set-variable -Wno-unused-parameter -Wno-unused-variable -Wno-shadow     -Wno-undefined-bool-conversion -O1 -DTOP_TYPE=VAdderTester -DVL_USER_FINISH -include VAdderTester.h   -c -o VAdderTester__ALLsup.o VAdderTester__ALLsup.cpp
g++  -I.  -MMD -I/usr/share/verilator/include -I/usr/share/verilator/include/vltstd -DVL_PRINTF=printf -DVM_COVERAGE=0 -DVM_SC=0 -DVM_TRACE=1 -faligned-new -Wno-sign-compare -Wno-uninitialized -Wno-unused-but-set-variable -Wno-unused-parameter -Wno-unused-variable -Wno-shadow     -Wno-undefined-bool-conversion -O1 -DTOP_TYPE=VAdderTester -DVL_USER_FINISH -include VAdderTester.h   -c -o VAdderTester__ALLcls.o VAdderTester__ALLcls.cpp
      Archiving VAdderTester__ALL.a ...
ar r VAdderTester__ALL.a VAdderTester__ALLcls.o VAdderTester__ALLsup.o
ar: creating VAdderTester__ALL.a
ranlib VAdderTester__ALL.a
g++    top.o verilated.o verilated_vcd_c.o VAdderTester__ALL.a    -o VAdderTester -lm -lstdc++  2>&1 | c++filt
make: Leaving directory '/srv/workspace/chisel/test_run_dir/AdderTester/201811141951384238257037378005420'
Enabling waves...
    passed step 0 -- out:   575
Starting simulation!
    passed step 1 -- out:   866
    passed step 2 -- out:   968
Stopping, end of tests, 4 steps
[success] Total time: 20 s, completed Nov 14, 2018 7:51:40 PM

这时，在 /srv/workspace/chisel/test_run_dir/AdderTester 文件夹中能找到相关的模块比如： *.v 以及 *.vcd 文件。

参考

Chisel实验笔记（二）
chisel-testers

Chisel 学习笔记 (一)

基础环境

iVerilog 使用方法

gtkwave 波形

开发环境

sbt 使用

参考

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