View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0003522 | PicoCoreBBRGB_HW | USB device | public | 2018-11-08 15:00 | 2019-03-20 09:08 |
| Reporter | Assigned To | ||||
| Priority | normal | Severity | minor | Reproducibility | always |
| Status | resolved | Resolution | fixed | ||
| Product Version | 1.10 | ||||
| Target Version | 1.20 | ||||
| Summary | 0003522: Protective diodes for USB do not work with ID pin | ||||
| Description | as we have just noticed, there is a problem if there is nothing plugged into the USB OTG1 socket. Then there is a "nice" interplay. 1: The OTG1 ID pin is pulled up by the pull-up, the port is switched to device function, the OTG1 PWR is switched off. This causes VBUS and thus the REF voltage on the protective diode chip to drop to 0V. However, the protective diode of the ID pin switches through and pulls the ID pin to Low. 2. 2. the port thinks: "Oops, I am a host" and switches on OTG1_PWR. This turns VBUS to 5V and thus also the REF voltage of the protection diode chip. But now the ID pin is no longer pulled to Low and goes back to High. 3. so the port thinks: "Oops, I'm a device" and returns to step 1. So the ID pin changes constantly between High and Low and so consequence the VBUS voltage is constantly switched on and off and the port is also reconfigured software-wise constantly between host and device. | ||||
