To manually test DCP/CDP features on the TUSB217AEVM-BC:
If the downstream device is not getting adequate VBUS toggle, to force a reconnect event the downstream device can be disconnected and reconnected or the external EVM power manually toggled:
Entering CDP mode from DCP mode:
- No jumper on Header 6 × 2, pin 9 (CDP_ENZ in the schematic)
- Power cycle the VCC_EXT_Px to the EVM or disconnect and reconnect the downstream device
Entering DCP mode from CDP mode:
- Jumper on header 6 × 2, pin 9 (CDP_ENZ in the schematic) to GND (pin 10 or 11).
- Power cycle the VCC_EXT_Px to the EVM or disconnect and reconnect the downstream device
Note: The VBUS toggle circuit on the TUSB217AEVM-BC should not be used as a reference design. The resistor divider used to sense upstream VBUS will back drive voltage on upstream VBUS due to the internal pullup on DCP/CDP. A design with a comparator is recommended.