Hello,
I'm using TI’s USB PHY chip(TUSB1310A) on a emulation platform.
When the platform worked as SS device mode(host side is a PC), we frequently saw a U0<->RECOVERY issue.
We dumped a USB trace like below, but sometimes when device side(our platform) replied LGOOD_4 to host_pc, host_pc couldn’t receive it successfully, after 3us’ time out,
Host_pc would send TS1 packet, causing our platform to go to RECOVERY state frequently.
We checked our device digital design part and haven’t found obvious issue there, so we suspect the signal quality on USB daughter card is not so good there.
So I have several questions:
1. For external USB PHY, any settings/config. can help to improve signal quality?
2. Have you been reported for similar case?
3. Do you have any suggestion for debugging this issue?
Thanks,
Hayden