An idea is brought forth to design the total structure of the usb interface ip , the main control logic , the mcu interface ( the function is the same as the pdiusbd12 chip of the philips semiconductor ) and a dpll which is used to synchronize data and separate the clock . this paper also introduces packet recognition , transaction sequencing , sop , eop , reset , resume signal detection / generation , nrzi data encoding / decoding and bit - stuffing , crc generation and checking ( token and data ) , packet id ( pid ) generation and checking / decoding , 提出設計了usb接口電路的整體構架,設計了usb的主要控制邏輯和與mcu的互連的接口(此接口與飛利普的usb接口芯片pdiusbd12兼容) ,也設計了一個數字鎖相環( dpll )來同步數據和分離時鐘,并對同步模式的識別、并行/串行轉換、位填充/解除填充、 crc校驗/產生、 pid校驗/產生、地址識別和握手評估/產生做了具體的分析。
At the same time , this paper presents packet recognition , transaction sequencing , sop , eop , reset , resume signal detection / generation , clock / data separation , nrzi data encoding / decoding and bit - stuffing , crc generation and checking ( token and data ) , packet id ( pid ) generation and checking / decoding , serial - parallel / parallel - serial conversion 對同步模式的識別、并行/串行轉換、位填充/解除填充、 crc校驗/產生、 pid校驗/產生、地址識別和握手評估/產生做了具體的分析。