➤ Fomu 開發板上的 SPI 路由與韌體重置技巧
✤ https://danielmangum.com/posts/spi-routing-ice40-fpga/
本文深入探討如何在 Lattice iCE40 FPGA 上實現 SPI 路由,特別是以 Fomu 開發板為例。作者詳細解釋了 Fomu 如何在不包含實體 USB 硬體的情況下,透過 RTL 實作 USB 核心,並將其整合到 Foboot 載入程式中。文章也闡述了 iCE40 FPGA 的配置選項,包括直接寫入 SRAM、從外部 SPI Flash 讀取,或是一次性編程 NVCM。作者藉由分析 Fomu 的電路圖,揭示了即使只有一個 SPI Chip Select (CS) 訊號,也能夠同時處理 FPGA 作為主機(讀取 Flash)和從機(被外部程式設計),以及如何透過重設 FPGA 的 CRESET 訊號,在 FPGA 處於重設狀態時,得以安全地對外部 SPI Flash 進行程式設計,進而實現對
#FPGA #iCE40 #SPI #Fomu #韌體開發
Interesting SPI Routing with iCE40 FPGAs
A few weeks ago I posted about how much fun I was having with the Fomu FPGA development board while travelling. This project from Tim ‘mithro’ Ansell and Sean ‘xobs’ Cross is not new, but remains a favorite of mine because of how portable it is — the entire board can fit in your USB port! The Fomu includes a Lattice Semiconductor iCE40 UltraPlus 5K, which has been a popular FPGA option over the past few years due to the reverse engineered bitstream format and ability to program it with a fully open source toolchain (see updated repository here).









