Table 3-13 'DBfg' - Clear
Dead Battery Flag
Description |
The 'DBfg' Task is
used to clear the dead battery flag. This Task does not disable the PP_EXT input
switch that may have been enabled during dead battery operation. |
INPUT DATAX |
None. |
OUTPUT DATAX |
None. |
Task Completion |
The 'DBfg' Task completes after the effects of clearing
the Dead Battery Flag are complete. |
Side Effects |
The Dead Battery Flag causes the PD Controller to take
specific actions, so clearing this flag will have side effects. PD Controller 's
power input is forced to VBUS until the Dead Battery Flag is cleared, so executing
this Task will change PD Controller 's power input. |
Additional Information |
None. |
There are several limitations placed on the PD controller while the Dead-Battery Flag
is asserted (PowerPathStatus.PowerSource = 10b).
- A Hard Reset will not be transmitted
while in the sink role (on either port).
- VBUS is selected as the main supply for
the PD controller, even if the 3.3 V input is present.
- The PD controller will reject PR_Swap
requests to become source (on either port).
- The 2nd port in the PD controller that is
unconnected will only offer the USB Type-C Default Rp (PortControl.TypeCCurrent is
ignored) if it connects as a source.
- A port connected to a source will only
act as a Type-C sink regardless of the configuration.
- If no Source Capabilities message is
received after the boot process is complete (Status.ActingAsLegacy=11b), the PD controller
will not send a Hard Reset until the Dead-Battery Flag is cleared even if the
SinkWaitCapTimer expires.