Freescale Semiconductor MPC5200B - Manual (Page 425)

MPC5200B Users Guide, Rev. 1
12-22 Freescale Semiconductor
Host Control (HC) Operational Registers
12.4.5.4 USB HC Rh Port1 Status Register—MBAR + 0x1054
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.
Bits Name Description
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.