Content originally posted in LPCWare by new_user on Fri May 13 08:35:19 MST 2016
Device: LPC1768
[u]Test 1[/u]
Action: I connect wire from USB_OVRCR to ground
What happen:
[list]
[*] USB_OVRCR pin state change: 1 => 0
[*] OcRhPortStatus1 change: 0x00000100 => 0x00080000
[*] USB_PPWR pin state change: 0 => 1
[/list]
=> Overcurrent protection work. OHCI automatically turn USB port power off.
[u]Test 2[/u]
Action: I connect write from USB +5V pin to ground (real overcurrent situation)
What happen:
[list]
[*] USB_PWRD pin state change: 1 => 0
[*] USB_OVRCR pin state change: 1 => 0
[/list]
=> That's all. Overcurrent protection not work. OHCI not response at all (OcRhPortStatus1 is still 0x00000100).
Is this normal? Why OHCI not response test case 2?
