最近调试CY7C68013A发现在枚举之前就进入了高速模式,以下是串口打印信息:
- HI-SPEED
- URES
- HI-SPEED
- SUDAV
- 80 06 00 01 00 00 40 00
- EXIT
- URES
- HI-SPEED
- SUDAV
- 80 06 00 01 00 00 12 00
- EXIT
- SUDAV
- 80 06 00 02 00 00 FF 00
- EXIT
- SUDAV
- 80 06 03 03 09 04 FF 00
- EXIT
- SUDAV
- 80 06 00 03 00 00 FF 00
- EXIT
- SUDAV
- 80 06 02 03 09 04 FF 00
- EXIT
- SUDAV
- 80 06 00 01 00 00 12 00
- EXIT
- SUDAV
- 80 06 00 02 00 00 09 00
- EXIT
- SUDAV
- 80 06 00 02 00 00 27 00
- EXIT
- SUDAV
- 00 09 01 00 00 00 00 00
- EXIT
复制代码1、USB协议里面设备枚举应该是在全速模式下进行的,而从打印信息来看,复位(URES)之后立刻就进入了高速模式,随后开始枚举,获取各种描述符(80H,06H,...,)后,主机SetConfig(00H,09H,...,),枚举完成,这个过程有点不理解。。
2、主机并没有向设备请求DeviceQualifier描述符,那HOST如何知道这个设备支持高速呢?
一周热门 更多>