Freescale Semiconductor MPC5200B ユーザーズマニュアル

12-22

Freescale Semiconductor

This register is controls and reports port events on a per-port basis. The Number of Downstream Ports (NDP) represents the number of 
HcRhPortStatus registers that are implemented in hardware. The lower 16-bits is used to reflect the port status; the upper 16-bits reflects the 
status change bits. MPC5200B has NDP = 2, therefore, HcRhPort1Status (MBAR + 1054) and HcRhPort2Status (MBAR + 1058).

Some status bits are implemented with special write behavior. If a transaction (token through handshake) is in progress when a write to change 
port status occurs, the resulting port status change is postponed until the transaction completes. Reserved bits should always be written 0.

0

CRWE

ClearRemoteWakeUpEnable (write)

•

Writing 1 clears DRWE.

•

Writing 0 has no effect.

1:13

—

Reserved

14

OCIC

OverCurrentIndicatorChange—is set by hardware when a change occurs to the OCI field of 
this register.

•

Writing 1 causes HCD to clear this bit.

•

Writing 0 has no effect.

15

LPSC

LocalPowerStatusChange (read)—Root Hub does not support the local power status feature. 
Thus, this bit is always read as 0. 

SetGlobalPower (write)

•

In global power mode (PSM=0), LPSC is written to 1 to turn on power to all ports (clear 
PortPowerStatus).

•

In per-port power mode, LPSC sets PortPowerStatus only on ports whose PPCM bit is not 
set. 

Writing 0 has no effect.

16

DRWE

DeviceRemoteWakeUpEnable (write)—enables a ConnectStatusChange bit as a resume 
event, causing a USBSUSPEND to USBRESUME state transition and setting the 
ResumeDetected interrupt.

0 = ConnectStatusChange is not a remote WakeUp event.

1 = ConnectStatusChange is a remote WakeUp event.

SetRemoteWakeUpEnable (read). 

1 = Sets DRWE.

0 = Has no effect.

17:29

—

Reserved

30

OCI

OverCurrentIndicator—reports overcurrent conditions when global reporting is implemented. 

When set, an overcurrent condition exists.

When cleared, all power operations are normal. 

If per-port overcurrent protection is implemented this bit is always 0.

31

LPS

LocalPowerStatus—Root Hub does not support the local power status feature. This bit is 
always read as 0 (write) ClearGlobalPower.

In global power mode (PSM=0), bit is written to 1 to turn off power to all ports (clear 
PortPowerStatus).

In per-port power mode, bit clears PortPowerStatus only on ports whose PPCM bit is not 
set.

Writing 0 has no effect.