综合时 with-select-when 缺少选择项报错
综合 Synth 社区未闭环 Vivado
一句话结论：with-select-when 缺少选择项导致综合报 Synth 8-426
综合因 with-select-when 语句缺少选择项而失败，设 when others 为 null 等无效
[Synth 8-426] missing choice(s) error during synthesis
帖中未明确
with-select-when 缺少选择项导致综合报 Synth 8-426
本文据 AMD 客户社区（原 Xilinx 论坛）真实报错帖整理为中文要点，非原文转载；技术细节以原帖与 AMD 官方文档为准。
原帖：https://adaptivesupport.amd.com/s/question/0D52E00007G0jIBSAZ/synth-8426-missing-choices-err…