VHDL tutorial - A practical example - part 1 - Hardware
Gene Breniman walks through a practical CPLD-based data acquisition engine built for a low-power handheld instrument, focusing on hardware choices, signal flow, and pin assignments. The article explains component selection including a PCM1870 ADC, CY14B101Q2 serial nvSRAM, and an XC2C64A CPLD, and shows how the CPLD acts as an SPI sequencer and I2S clock master while minimizing microcontroller pins and power draw.
Introduction to FPGA Technology
Muhammad Yasir lays out a concise primer on FPGA fundamentals, covering internal architecture, vendors, and practical selection criteria. He explains how logic cells, LUTs, flip-flops, carry chains, block RAM, and I/O blocks combine to determine capacity and performance. This friendly overview shows why FPGAs beat ASICs for low-volume or rapidly changing designs, and how to match device resources to your application needs.
FPGA Bloggers Needed - New Reward System
You can earn up to $500 for a single FPGA blog post on FPGARelated. Stephane Boucher announces a new pageview-based reward system that pays $25 for every 250 unique pageviews, capped at $500 when a post reaches 5,000 views. If you write about Verilog, VHDL, or FPGA design and want to share expertise while getting paid, fill the short application form to apply.
USB-FPGA : Introduction
Christopher Felton recounts a six-year hobby project to build an open-source USB-FPGA board and its toolchain, from PCB to gateware, firmware, and PC software. He explains why the Cypress FX2 and a Spartan3 were chosen, how the USBP framework supported multiple boards, and why the project’s open-source ambitions didn’t attract the collaboration he expected. Expect practical design and community lessons.
Half-band filter on Xilinx FPGA
Lyons Zhang shows a practical, high-throughput implementation of a symmetric systolic half-band FIR on Xilinx FPGAs using DSP48 slices. The post includes a two-channel interleaved downsample-by-2 Verilog module, pipeline mapping to DSP48, and a symmetric rounding trick to reduce the DC shift from truncation. It highlights performance-and-latency tradeoffs and gives working code you can drop into a Spartan-6 style flow.
A Bit Bucket had Holes
Christopher Felton looks back at TierLogic's multi-layer FPGA idea and its recent shutdown, contrasting it with Tabula's virtual 3D approach. He asks whether physical-layer stacking could have delivered the ultra-high logic density some designs need, especially at modest clock rates and small footprints. The post highlights how funding, market fit, and patent outcomes often decide whether neat FPGA tech becomes a product.
Developing FPGA-DSP IP with Python
Designing FPGA-DSP IP entirely in Python is practical and productive, as Christopher Felton demonstrates using MyHDL. He shows how numpy and scipy handle the signal design while a SIIR class generates RTL, enables side-by-side floating-point and HDL simulation, and converts to Verilog for synthesis. The post includes Xilinx XC3S500E resource results and a link to the SIIR source on BitBucket, making it easy to try the workflow.
Holy Bit Bucket
Christopher Felton reacts to Tabula's 'Spacetime' pitch, which claims an 8x boost in LUT density by time-division multiplexing internal logic. He urges caution, comparing Tabula to Achronix and pointing out that early parts will likely target high-end networking and carry premium pricing. The post argues inexpensive development boards will be crucial for wider adoption.
The Spartans
Christopher Felton walks through the Spartan6 FPGA basics, explaining CLBs, slices, and the new 6-input LUTs while comparing them to Spartan3. He ran timing-driven mappings of real gateware to show practical LUT utilization differences. The post gives a pragmatic estimate of expected LUT savings and points out where mapping results can vary depending on the design.
New Design - Finally!
Stephane has finally applied a modern design to FPGARelated.com, bringing the site in line with DSPRelated.com and EmbeddedRelated.com. After a long todo list the refreshed layout and updated styling are live, promising a cleaner, more consistent experience across his engineering sites. Drop by to explore the new look and share feedback with the author.
Introduction to FPGA Technology
Muhammad Yasir lays out a concise primer on FPGA fundamentals, covering internal architecture, vendors, and practical selection criteria. He explains how logic cells, LUTs, flip-flops, carry chains, block RAM, and I/O blocks combine to determine capacity and performance. This friendly overview shows why FPGAs beat ASICs for low-volume or rapidly changing designs, and how to match device resources to your application needs.
MyHDL Resources and Projects
Christopher Felton has pulled together a compact, practical guide to learning and using MyHDL, with the essential manual, Jan Decaluwe's deep dives, presentations, example projects, and active Git/Bitbucket repos. Whether you want a tutorial path, reference reads, or hands-on FPGA projects from simple LEDs to SDR and DSP cores, this curated list points you to vetted resources and real designs to study and reuse.
Summer of gateware is coming (again)
Wondering what gateware will come out of this summer? Christopher Felton announces MyHDL is back in Google Summer of Code and has been awarded six student slots. Projects span GEMAC, a Leros tiny processor, JPEG encoder front/backends, RISC-V tooling and HDMI+RISC-V work. Follow along for short project updates and a final summer summary.
Designing a FPGA Micro Pt2 - Clock and Counter build and test.
Paul J Clarke continues building his PIC12F509-style soft core by implementing the clock and program counter. He walks through a simple clock_gen.vhd that rotates a four-bit shift register to produce Q1 to Q4 phases, wires it into monpjc_pic_core.vhd for a XuLA target, and adds a 12-bit integer pc_counter that increments on Q1. The post shows simulation testbench results and previews stack and memory work next.
Choosing an Implementation Approach
I outline why I chose a CPU-like Graph Cut Processing Unit for FPGA-based graph-cut work, contrasting whole-problem and streaming approaches from the literature. The plan maps push-relabel style augmenting-path iterations to a simple GCPU state machine and pseudocode, prioritizing staged, testable development now and leaving highly parallel streaming scaling for later.
Designing a FPGA Micro Pt1 - Start The Clock
Paul J Clarke takes on cloning a Microchip PIC12F509 inside an FPGA, picking it for its tiny, well-documented architecture. He outlines the core pieces you'll need: 1024×12-bit ROM, 41 bytes of RAM, an ALU, status register, program counter with a two-level stack, GPIO, and the PIC's unusual four-phase internal clock. This post sets the plan and previews the next installment with the first implementation work.
Holy Bit Bucket
Christopher Felton reacts to Tabula's 'Spacetime' pitch, which claims an 8x boost in LUT density by time-division multiplexing internal logic. He urges caution, comparing Tabula to Achronix and pointing out that early parts will likely target high-end networking and carry premium pricing. The post argues inexpensive development boards will be crucial for wider adoption.
My VHDL <= monpjc; Journey
Paul J Clarke (monpjc) traces his VHDL journey from Altera SDRAM interfaces to hobby MAX7000 projects and how affordable dev kits rekindled his FPGA hobby. He explains why he prefers VHDL, why Xilinx ISE won him over, and urges engineers to learn by doing with simple projects. The post offers practical kit recommendations and teases a follow-up series on building a CPU on an FPGA.
Yet another PWM
The provided record for Anton Babushkin’s post “Yet another PWM” contains no article body, so the actual technical content is not available for review. The title and site context indicate the post concerns pulse-width modulation (PWM), but specific implementation details, language, or examples cannot be confirmed from the supplied input. This metadata therefore documents the absence of content, recommends steps to recover the original post, and flags that any downstream use (tagging, excerpts, or code extraction) must wait until the full text is retrieved from FPGARelated’s archive or the author’s copy to avoid misrepresentation.
MyHDL ... MyPWM
Christopher Felton presents a compact MyHDL PWM engine designed to be configured at design time and targeted for FPGA synthesis. The module derives PWM bit width from the system clock frequency and desired pwm_frequency, truncates inputs when necessary, and prints parameter summaries for different clock/pwm combinations. The post includes the full MyHDL source and a simulation waveform showing the input signal and the modulated output, making it easy to reproduce.
Homebrew CPUs: Color Languages
Victor Yurkovsky proposes turning color from mere syntax highlighting into a semantic tool for a Forth-like CPU, letting color pick which stack an operation touches. He outlines a "Rainbow Forth" where green and blue select two datastacks, red denotes the return stack, gray means use the caller's color, and white is neutral. The post sketches CPU changes, a COLOR register, call encoding and immediate-mode coloring, and teases editor and compiler implications for implementing this idea on a J1-style core.
MyHDL ... MyPWM
Christopher Felton presents a compact MyHDL PWM engine designed to be configured at design time and targeted for FPGA synthesis. The module derives PWM bit width from the system clock frequency and desired pwm_frequency, truncates inputs when necessary, and prints parameter summaries for different clock/pwm combinations. The post includes the full MyHDL source and a simulation waveform showing the input signal and the modulated output, making it easy to reproduce.
Point of View
Christopher defends a straightforward MyHDL RTL description of a FIR filter, arguing it is explicit, readable, and concise. He compares that style to a functional hardware description built with Python primitives and list comprehensions, and finds both convert to identical synthesis resources for this example. The post highlights readability tradeoffs and suggests choice often comes down to background and preference.
Cutting a Path Forward
As a software developer building a drone navigation prototype, the author turned to FPGAs after realizing CPUs and cloud tethering break the "simple, cheap, reliable" constraints. He proposes mapping sensor probabilities into a graph-cut network using negative log-likelihoods to produce risk‑averse, real‑time path planning, aiming for tens of milliseconds. The post explains the graph-cut idea, cites FPGA precedents, and lays out a practical FPGA-focused plan of attack.
[Comments] C HLS Benefits
Christopher Felton argues C-to-gate HLS showed little advantage in his median calculation comparison with MyHDL. He explains the test mixes language paradigm and abstraction: Vivado C HLS is an imperative, step-by-step style while MyHDL offers a concurrent, HDL-level description with Python's readability and elaboration features. He notes C-HLS can help if you only know C, but for massively parallel FPGA work non-C tools may be preferable.
Are you kidding me?
Christopher Felton pushes back on the idea that C/C++/SystemC are the natural path to higher-abstraction FPGA design. He argues hardware designers often do not use C-family languages for modeling and simulation, so choosing C as the HLS lingua franca may be more about tool momentum than suitability. The post urges reconsidering languages with higher abstraction and lower cost of entry for system modeling and HLS.
Choosing an Implementation Approach
I outline why I chose a CPU-like Graph Cut Processing Unit for FPGA-based graph-cut work, contrasting whole-problem and streaming approaches from the literature. The plan maps push-relabel style augmenting-path iterations to a simple GCPU state machine and pseudocode, prioritizing staged, testable development now and leaving highly parallel streaming scaling for later.
MyHDL Presentation Examples
Christopher Felton collected slide-ready MyHDL demos he used at EELive and PyOhio, making it easy to see practical HDL examples in action. The post explains the tradeoffs behind single-slide examples, links to 2013 and 2014 demos from simple FPGA hello-worlds to filters and a VGA system, and points readers to the repository where full and larger examples live for reuse.
Summer of gateware is coming (again)
Wondering what gateware will come out of this summer? Christopher Felton announces MyHDL is back in Google Summer of Code and has been awarded six student slots. Projects span GEMAC, a Leros tiny processor, JPEG encoder front/backends, RISC-V tooling and HDMI+RISC-V work. Follow along for short project updates and a final summer summary.
MyHDL @EDAPlayground
MyHDL just got easier to try: it's available on EDAPlayground, so you can run Python-based HDL verification directly in the browser. The two-panel editor places the testbench on the left and the HDL under test on the right, with public examples such as a simple strobe and a RAM test ready to copy. Christopher Felton also links a curated resource list to help you get started quickly.
