幀首定界符 sfd start frame delimiter: 幀起始定界符start frame delimiter sfd: 8字節(jié); 包含7字節(jié)的起始幀分界符; 幀起始定界符/同步start of frame delimiter: 幀首定界符start delimiter: 起始分界符sd start delimiter: 起始定界符下載手機詞典可隨時隨地查詞查翻譯