For quite a while I have followed the RISC-V ISA with growing intereset. Now that RISC-V is becoming more and more popular and catching a lot of public attention, it is time to get my hands dirty with some low level RISC-V assembly coding.
Author: andrsmllr Page 2 of 6
There are a lot of FPGA development boards out there to buy. Official vendor boards with the latest advanced devices on it can easily cost several thousand Euros.
Hobbyists and makers are more interested in FPGA development boards within an affordable price range (roughly << 100 $/€). The logic resources and feature set of the FPGA devices on these boards is not that important on the other hand. The main application for makers/hobbyists is small projects and self-learning, I assume, and not rolling out their own 5G equipment.
The iCEBreaker board is the first FPGA development board with a fully open-source toolchain, which allows to go all the way from HDL code to configuration bitstream. All the schematics and hardware information is openly available at no extra cost.
The Longan Nano is a new contestor in the area of affordable RISC-V development boards. The Longan Nano’s form factor and price puts it up against the Arduino Nano and all other varieties of STM32-based “nano boards”, which can be found abundantly on Ebay and AliExpress.
Magic VLSI – or just Magic – is a free and open source VLSI layout software. Simply put Magic allows you to draw the mask layers used in a semiconductor facrication process. The Magic software is another “Berkeley Child” (like BSD and others) and first came into existence in the 1980s. Magic is still under active development as of late 2019.
Some Linux distributions offer a pre-build package for Magic from their package repository. Most often these packages are outdated and therefor it is best to build Magic from the sources.
If you haven’t heard of GHDL, it is *the* free open-source VHDL simulator out there.
GHDL stand for “G Hardware Description Language” (the G is without meaning). GHDL is mainly implemented in Ada and can be build with different backends: mcode, LLVM and GCC. The different backends provide different performance levels and vary in build complexity. I recommend LLVM since it performs well and is still quite straight forward to build. Building GHDL from latest sources from its github project is probably the best way to go.
Despite its free nature GHDL provides very good support for all major VHDL-LRM releases: VHDL-1987/1993/200X/2008(partial). Unfortunately GHDL is a pure VHDL simulator, so there is no support for Verilog at all. This is understandable as there are already some very good simulators for Verilog out there.
In the past I used USBtiny and USBasp programmers to flash Atmel microcontrollers. Under Windows 10 the programmers did not work, even though Windows 10 seemed to detect them correctly.
It turns out Windows 10 does not use/fetch the correct drivers.
To make things work again most folk use Zadig a tool which automatically installs some legacy drivers typically used for USB programmer dongles.
After the drivers are installed Windows 10 finally detects my USBasp programmer dongle as it should.
Recently I purchased a Sipeed TANG PriMER development board featuring an Anlogic EG4S20 FPGA (codenamed Eagle S20). The only reason I bought the board was to see what Anlogic FPGAs are capable of, since I had never heard of that FPGA vendor before. No need to think twice when the board costs less than 20$.