The usb 2.0 hub design is follow TUSB4041PAPEVM Schematic. And use the external eeprom for PID/VID setting. The eeprom bin file is showed as picture.
In our application, the Host is the Mac mini (mac OS system). The hub is used to communicate with our product, and the product will power cycle which means the device will disappear and reconnect.
There exist a strange phenomenon: if the hub first power on ; or mac mini restart ; the hub will drop (the mac mini can't read hub device) still for about 6s when our product power cycle and reconnect. And It is particularly important to note that this phenomenon only occurs under the conditions mentioned above.
We capture the data of USB, and show error as below photo. Could you please help analyze it and provide some suggestions?











如接线图所示,端口1和2均接的是待测试的设备。且测试过程中,待测试设备的两组USB在测试过程中会有断开重连的步骤(每轮测试都是一样的步骤,但是hub的断开重连只发生在上电的第一次)。而出现这个问题的时间点也是在设备USB断开重连的过程时发生的。所以使用过程中端口1、2都需要使用,没办法移除2端口进行测试。