博文

目前显示的是标签为“Intel FPGAs”的博文

Implementation of PCIe Interface on FPGA

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  Implementing a PCIe interface on an FPGA is a complex task that leverages specialized hard IP blocks within the FPGA. Here’s a detailed breakdown of the components, steps, and considerations involved. Core Concept: The PHY and the Hard IP Unlike simpler protocols (like UART or SPI), you cannot implement PCI Express efficiently using just FPGA logic fabric (the "soft" programmable logic). This is because the PCIe physical layer (PHY) requires: High-Speed SerDes (Serializer/Deserializer):  Operating at multi-gigabit rates (e.g., 2.5 GT/s for Gen1, 5.0 GT/s for Gen2, 8.0 GT/s for Gen3). Complex Analog Circuits:  For clock data recovery (CDR), impedance matching, and pre-emphasis. Therefore, all modern FPGAs capable of PCIe contain  dedicated hard IP blocks  for the PHY and the controller logic. Your job is to  configure  this hard IP and  connect  it to your user logic within the FPGA fabric. Key Components of a PCIe Implementation PCIe Hard ...

Common FPGA I/O Interface Standards

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  FPGAs ( Field-Programmable Gate Arrays ) support various   I/O interface standards   for communication with external devices. These standards define voltage levels, signaling methods, and protocols. Below are the most commonly used ones: 📌 1. Single-Ended Standards (One signal line per data bit, referenced to ground.) Standard Voltage Speed Use Case LVCMOS  (Low-Voltage CMOS) 1.2V, 1.8V, 2.5V, 3.3V < 500 Mbps GPIO, slow peripherals LVTTL  (Low-Voltage TTL) 3.3V < 100 Mbps Legacy systems, microcontrollers HSTL  (High-Speed Transceiver Logic) 1.5V ~ 200 Mbps Memory interfaces (QDR, DDR) SSTL  (Stub-Series Terminated Logic) 1.8V, 2.5V ~ 400 Mbps DDR SDRAM interfaces 📌 2. Differential Standards (Uses two complementary signals for noise immunity & high speed.) Standard Voltage Speed Use Case LVDS  (Low-Voltage Differential Signaling) 350 mV (differential) 1+ Gbps High-speed serial links (cameras, displays) RSDS  (Reduced Swing Diffe...