BML Designing RISC-V SoCs with FPGAs : Part-GNU Cross-Compiler

2025.08.31 : I’m Kevin Hubbard, Electrical Engineer. I’ve spent the majority of my 30+ year career designing digital logic circuits in ASICs and FPGAs. It’s been an amazing journey that I hope others will pursue. I’m giving back now in writing this “BML Designing RISC-V SoCs with FPGAs” series which starts here.

This chapter explains installing and using the GNU GCC Cross-Compiler tool-chain for compile bare-metal C code into RISC-V machine code.

At the beginning of time, CPUs were programmed in assembly language. Assembly is fine for small projects, and was easy enough to learn back in the 8-bit...

BML Designing RISC-V SoCs with FPGAs : Part-Intro

Table of Contents:
Part-1 : What are SoCs?
Part-2 : History of Modern Computer Architecture
Part-3 : RISC-V Assembly Language
Part-4 : RISC-V and the Femto core
Part-5 : Femto-CPU Memory Access
Part-6 : Femto-CPU Blinky in C
Part-7 : GNU cross-compiler
Part-8 : RISC-V and the KianV core
Part-9 : RISC-V and the Hazard3 core
Part-10 : Segger JTAG Debugger
Part-11 : Example Design – LED Blinky
Part-12: Example Design – UART Communications
Part-13 : Example Design – SPI Communications
Part-14 : Example Design – PWM Servo Controller
Part-15 : Example Design – VGA Graphics Controller
Part-16 : ? FreeRTOS ?

2025.08.31 : I’m Kevin Hubbard, BSEE. I’ve been designing with CPUs and digital...

XMS Support Now Available for the Lo‑tech 2MB EMS Board

New for the Lo-tech 2 MB EMS board: thanks to EXMS86 by Mateusz Viste, XT-class machines can now run XMS software — and even gain up to 64 KB of UMB from the EMS page frame.

The post XMS Support Now Available for the Lo‑tech 2MB EMS Board appeared first on lo-tech.

Project Showcase: Movuan

The Movuan project was started by community member lxb and announced in a forum post as an alternative to mobile distributions using the systemd init system. Thanks to being forked from Mobian, the project makes use of modified Mobian debos to build it’s images.

One of the modifications that lxb makes is an optional script which can customize a Movuan image to install extra software like...

Применение дешевых NFC меток NTAG213/215/216 работающих по стандарту ISO/IEC 14443A для дома и других сфер применения

Рассматриваются современные NFC метки NTAG213, NTAG215 и NTAG216 разработанные компанией NXP Semiconductors, работающие по стандарту ISO/IEC 14443-A. Эти метки очень популярны благодаря своей доступности, универсальности и совместимости с большинством NFC-считывателей, включая смартфоны. Фактор дешевизны и доступности определяет массовое распространение этих NFC-меток. Что такое NFC NFC или Near Field Communication – это технология «связи ближнего действия». Она позволяет пользователям обмениваться информацией, просто поднося устройства друг к другу на расстояние до 10 см. По сути NFC это частный случай RFID (Radio Frequency Identification) — механизма радиочастотного обмена данными, хранящимися в так называемых транспондерах или метках, который основан на стандартах ISO/IEC 18092 NFC...

Why do people keep writing about the imaginary compound Cr2Gr2Te6?

I was reading the latest issue of the journal Science, and a paper mentioned the compound Cr2Gr2Te6. For a moment, I thought my knowledge of the periodic table was slipping, since I couldn't remember the element Gr. It turns out that Gr was supposed to be Ge, germanium, but that raises two issues. First, shouldn't the peer reviewers and proofreaders at a top journal catch this error? But more curiously, it appears that this formula is a mistake that has been copied around several times.

The Science paper [1] states, "Intrinsic ferromagnetism in these materials was discovered in Cr2Gr2Te6 and CrI3 down to the bilayer...

Here be dragons: Preventing static damage, latchup, and metastability in the 386

I've been reverse-engineering the Intel 386 processor (from 1985), and I've come across some interesting circuits for the chip's input/output (I/O) pins. Since these pins communicate with the outside world, they face special dangers: static electricity and latchup can destroy the chip, while metastability can cause serious malfunctions. These I/O circuits are completely different from the logic circuits in the 386, and I've come across a previously-undescribed flip-flop circuit, so I'm venturing into uncharted territory. In this article, I take a close look at how the I/O circuitry protects the 386 from the "dragons" that can destroy it.

August Update: Note-able Tablet Updates

Welcome back to another community update!...

A Quick Community Update on PinePhone Pro and What’s Next

Hey everyone! As many have noticed, the PinePhone Pro is currently out ot stock on the Pine Store. Unfortunately we have to deliver you the following news: the PinePhone Pro is officially discontinued. We were told it didn’t sell well enough to keep production going. But the good news for current owners are that spare parts will still be made for up to two years, depending on demand. Meanwhile, the trusty PinePhone (A64) is still alive and kicking, and Pine Store plans to keep it rolling for about two more years.

Right now,...

Candle Flame Oscillations as a Clock

Todays candles have been optimized for millenia not to flicker. But it turns out when we bundle three of them together, we can undo all of these optimizations and the resulting triplet will start to naturally oscillate. A fascinating fact is that the oscillation frequency is rather stable at ~9.9Hz as it mainly depends on gravity and diameter of the flame. 

We use a rather unusual approach based on a wire suspended in the flame, that can sense capacitance changes caused by the ionized gases in the flame, to detect this frequency and divide it down to 1Hz.

Tim's Blog

Posted at 2025-08-13 11:16:42 | Electronics | read on