FPGA

1. What Is a Parallel Interface? A parallel interface transmits multiple bits simultaneously across multiple data lines. As shown below, there are 8 to 32 or more data wires (D[7:0], D[31:0], etc.) between transmitter and receiver, along with a shared clock and control signals such as VALID and READY. ┌─────────────┐ ┌─────────────┐ │ Transmitter │ D[7:0] │ Receiver │ │ ├────────►│ │ │ │ CLK │ │ │ ├────────►│ │ │ │ VALID │ │ │ ├────────►│ │ └─────────────┘ └─────────────┘ Parallel Bus — 8 data bits transferred simultaneously each clock cycle ■ CLK ■ D[7:0] data ■ VALID Advantages: ...

An FPGA does not work in isolation. No matter how correct your RTL is, the design will fail if the power supply is noisy, the clock does not reach the device cleanly, or a digital interface is mismatched at the board level. FPGA engineers who can diagnose hardware problems are significantly more effective than those who can only debug RTL in simulation. This post covers the board-level skills that separate a junior FPGA engineer from a senior one. ...

When selecting an AMD/Xilinx FPGA you must specify three attributes beyond logic capacity and memory size: Speed Grade, Temperature Range, and Reliability Grade. Understanding all three helps you choose the right device — and avoid paying for more than you need. AMD UltraScale+ Device Ordering Information (Product Selection Guide) Speed Grade Speed Grade is a post-fabrication classification (binning) that reflects the worst-case switching performance of a specific chip coming off the wafer. Even chips from the same wafer lot will have small transistor-level variations — some will reliably meet tighter timing margins than others. Chips that can do so are assigned a higher (faster) speed grade. ...

What Is Quantization? In signal processing, quantization is the process of mapping a continuous range of values to a discrete (integer) set. In deep learning and hardware acceleration, it specifically refers to: Converting floating-point (FP32, FP16, or BF16) model weights and activations to lower-bit integers (INT8, INT4, etc.) in order to reduce memory footprint and computational cost. Quantization is the bridge that makes neural networks practical on resource-constrained hardware. Why Quantization Is Essential for FPGA CNN Implementation FPGAs have a fixed amount of logic, DSP slices, and BRAM. Floating-point arithmetic is expensive in all three dimensions: ...

What Is LeNet-5? LeNet-5 is a convolutional neural network (CNN) proposed by Yann LeCun and colleagues in 1998 for handwritten digit recognition (the MNIST dataset). It is widely regarded as the historical model that established the foundational concepts of modern deep learning: convolution, pooling, and hierarchical feature extraction. LeNet-5 architecture as shown in (LeCun et al., 1998) MNIST — 70,000 greyscale 28×28 images of handwritten digits ...

When implementing a network interface in RTL, you need a precise byte-offset map for every field in the frame. This post provides that reference for the most common combination: Ethernet II + IPv4 + UDP. Layer Stack [ Preamble (7B) + SFD (1B) ] ← handled by PHY/MAC, not in user datapath [ Ethernet II header ] [ IPv4 header ] [ UDP header ] [ Application data ] [ FCS / CRC-32 (4B) ] ← often stripped/added by MAC IP (configurable option in Xilinx TEMAC / Tri-MAC) Note: The preamble, SFD, and inter-packet gap (IPG) are inserted and stripped by the PHY/MAC layer and are typically not visible in the AXI-Stream user interface of a MAC IP core. ...

FPGAs are optimised for massive parallelism, but their on-chip memory resources are limited. Block RAM (BRAM) and UltraRAM (URAM) are fast and easy to use, but they typically provide only a few tens of megabits to a few hundred megabits of capacity. When your application needs gigabytes — high-resolution video frames, machine-learning weight tables, large look-up tables — external DDR memory becomes essential. Why External DDR Memory? Memory Type Location Typical Capacity Bandwidth Access Latency Distributed RAM On-chip (LUT-based) < 1 MB Very high 1 cycle Block RAM (BRAM) On-chip (dedicated) up to ~200 MB High 1–2 cycles UltraRAM (URAM) On-chip (UltraScale+) up to ~500 MB High 2–3 cycles External DDR Off-chip (dedicated chip) 1–16+ GB Medium-High ~50–100 ns For applications such as: ...

What Happened to FPGA Prices? Between 2020 and 2022, the semiconductor industry experienced what analysts called “chipflation” — a sustained, broad-based price increase driven by pandemic-related demand spikes, supply chain disruptions, and surging investment in AI and 5G infrastructure. FPGA manufacturers were not immune. AMD (Xilinx) and Intel (Altera) both cited rising TSMC wafer costs as justification for significant list-price increases — in some cases close to double the pre-pandemic price. Unlike commodity memory or microcontroller price spikes that eventually normalised, elevated FPGA prices have proven sticky. ...

디지털 데이터는 본질적으로 이진 비트(0과 1)의 집합이지만, 이를 실제 물리적 전송 매체(구리선, 광섬유 등)를 통해 송수신하려면 전기적 또는 광학적 신호로 변환하는 과정이 필수적이다. 이 변환 과정은 단순히 비트를 전압 레벨로 바꾸는 것 이상의 복잡한 기술적 과제를 수반한다. 가장 주요한 두 가지 과제는 DC 성분(직류 성분)의 축적과 수신기 클럭 동기화이다. 동일한 비트(예: ‘00000…’ 또는 ‘11111…’)가 장시간 연속되면 전압이 한쪽 극성으로만 유지되어 신호에 직류 성분이 누적된다. 또한, 신호의 전이(transition)가 사라져 수신기 측의 위상 동기 루프(Phase-Locked Loop, PLL) 회로가 클럭을 추출하지 못해 데이터 비트의 경계를 식별하는 데 실패한다. 이러한 문제들은 데이터 전송의 신뢰성과 무결성을 심각하게 저해한다. ...

The Limits of Parallel Buses Traditional parallel data buses were efficient at low clock rates, but as clock frequencies increased they ran into fundamental physical barriers. The core problem is timing skew: with many parallel data lanes plus a separate clock lane, each signal travels a slightly different path length on the PCB and through the package, arriving at the receiver at slightly different times. As the clock period shrinks, even a small skew becomes a significant fraction of a bit period, and data errors follow. ...