Chisel 教程翻译 《Digital Design with Chisel》
倩图已献，心神灿烂
《Digital Design with Chisel》20201010版本
Second Edition Martin Schoeberl
https://creativecommons.org/licenses/by-sa/4.0/
Attribution-ShareAlike 4.0 International (CC BY-SA 4.0)
This is a human-readable summary of (and not a substitute for) the license. Disclaimer.
You are free to:
- Share — copy and redistribute the material in any medium or format
- Adapt — remix, transform, and build upon the material
- for any purpose, even commercially.
Foreword
It is an exciting time to be in the world of digital design. With the end of Dennard
Scaling and the slowing of Moore’s Law, there has perhaps never been a greater need
for innovation in the field. Semiconductor companies continue to squeeze out every
drop of performance they can, but the cost of these improvements has been rising drastically. Chisel reduces this cost by improving productivity. If designers can build more in
less time, while amortizing the cost of verification through reuse, companies can spend
less on Non-Recurring Engineering (NRE). In addition, both students and individual
contributors can innovate more easily on their own.
Chisel is unlike most languages in that it is embedded in another programming language, Scala. Fundamentally, Chisel is a library of classes and functions representing
the primitives necessary to express synchronous, digital circuits. A Chisel design is really a Scala program that generates a circuit as it executes. To many, this may seem
counterintuitive: “Why not just make Chisel a stand-alone language like VHDL or SystemVerilog?” My answer to this question is as follows: the software world has seen a
substantial amount of innovation in design methodology in the past couple of decades.
Rather than attempting to adapt these techniques to a new hardware language, we can
simply use a modern programming language and gain those benefits for free.
A longstanding criticism of Chisel is that it is “difficult to learn.” Much of this perception is due to the prevalence of large, complex designs created by experts to solve
their own research or commercial needs. When learning a popular language like C++,
one does not start by reading the source code of GCC. Rather, there are a plethora of
courses, textbooks, and other learning materials that cater toward newcomers. In Digital
Design with Chisel, Martin has created an important resource for anyone who wishes to
learn Chisel.
Martin is an experienced educator, and it shows in the organization of this book. Starting with installation and primitives, he builds the reader’s understanding like a building,
brick-by-brick. The included exercises are the mortar that solidifies understanding, ensuring that each concept sets in the reader’s mind. The book culminates with hardware
generators like a roof giving the rest of the structure purpose. At the end, the reader is
left with the knowledge to build a simple, yet useful design: a RISC processor.
In Digital Design with Chisel, Martin has laid a strong foundation for productive
digital design. What you build with it is up to you.
Jack Koenig
Chisel and FIRRTL Maintainer
Staff Engineer, SiFive