Freescale Semiconductor MCF54455 Reference Manual page 244

Field
3 Port enable/disable change. For the root hub, this bit gets set only when a port is disabled due to disconnect on the
PEC port or due to the appropriate conditions existing at the EOF2 point (See Chapter 11 of the USB Specification).
Software clears this by writing a 1 to it.
In device mode, the device port is always enabled. (This bit is zero).
0 No change.
1 Port disabled.
This field is cleared if the PP bit is cleared.
2 Port enabled/disabled.
PE Host mode:
Ports can only be enabled by the controller as a part of the reset and enable sequence. Software cannot enable
a port by setting this bit. A fault condition (disconnect event or other fault condition) or host software can disable
ports. The bit status does not change until the port state actually changes. There may be a delay in disabling or
enabling a port due to other host and bus events.
When the port is disabled, downstream propagation of data is blocked except for reset. This field is cleared if the
PP bit is cleared in host mode.
Device mode:
The device port is always enabled. (This bit is set).
1 Connect change status.
CSC Host mode:
This bit indicates a change occurred in the port's current connect status. The controller sets this bit for all changes
to the port device connect status, even if system software has not cleared an existing connect status change. For
example, the insertion status changes twice before system software has cleared the changed condition; hub
hardware is setting an already-set bit (i.e., the bit remains set). Software clears this bit by writing a 1 to it. This
field is cleared if the PP bit is cleared.
0 No change.
1 Connect status has changed.
In device mode, this bit is undefined.
0 Current connect status. Indicates that a device successfully attaches and operates in high speed or full speed as
CCS indicated by the PSPD bit. If clear, the device did not attach successfully or forcibly disconnects by the software
clearing the USBCMD[RUN] bit. It does not state the device disconnected or suspended. This field is cleared if the
PP bit is cleared in host mode.
0 No device present (host mode) or attached (device mode)
1 Device is present (host mode) or attached (device mode)
10.3.4.15 On-the-Go Status and Control Register (OTGSC)
This register is not defined in the EHCI specification. The host controller implements one OTGSC register
corresponding to port 0 of the host controller.
The OTGSC register has four sections:
• OTG interrupt enables (read/write)
• OTG interrupt status (read/write to clear)
• OTG status inputs (read-only)
• OTG controls (read/write)
The status inputs de-bounce using a 1 ms time constant. Values on the status inputs that do not persist for
more than 1 ms do not cause an update of the status inputs or an OTG interrupt.
Freescale Semiconductor
Table 10-33. PORTSC1 Field Descriptions (continued)
Universal Serial Bus Interface – On-The-Go Module
Description
10-37