Freescale Semiconductor MPC5200B ユーザーズマニュアル
MPC5200B Users Guide, Rev. 1
12-26
Freescale Semiconductor
Host Control (HC) Operational Registers
12.4.5.5
USB HC Rh Port2 Status Register—MBAR + 0x1058
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 word is used to reflect the port status; the upper word reflects the
status change bits. MPC5200B has NDP = 2, therefore, HcRhPort1Status (MBAR + 1054) and HcRhPort2Status (MBAR + 1058).
HcRhPortStatus registers that are implemented in hardware. The lower word is used to reflect the port status; the upper word 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.
port status occurs, the resulting port status change is postponed until the transaction completes. Reserved bits should always be written 0.
30
PES
PortEnableStatus (read)—indicates whether the port is enabled or disabled.
The Root Hub may clear this bit when the following conditions are detected:
•
an overcurrent condition
•
disconnect event
•
switched-off power
•
operational bus error (such as babble)
This change causes PESC to be set. HCD sets this bit by writing SetPortEnable and clears it
by writing ClearPortEnable.
by writing ClearPortEnable.
PES cannot be set when CurrentConnectStatus is cleared. If not already set, PES is set at the
completion of a port reset when ResetStatusChange is set or port suspend when
SuspendStatusChange is set.
completion of a port reset when ResetStatusChange is set or port suspend when
SuspendStatusChange is set.
0 = port is disabled
1 = port is enabled
SetPortEnable (write)—HCD sets PES by writing 1. Writing 0 has no effect.
If CCS is cleared, this write does not set PES, but instead sets CSC. This notifies the driver
that an attempt was made to enable a disconnected port.
that an attempt was made to enable a disconnected port.
31
CCS
CurrentConnectStatus (read)—reflects current state of downstream port.
0 = No device connected
1 = Device connected
ClearPortEnable (write)—HCD writes 1 to this bit to clear PortEnableStatus bit. Writing 0 has
no effect. CCS is not affected by any write.
no effect. CCS is not affected by any write.
Note: This bit is always read ‘1b’ when the attached device is non-removable
(DeviceRemoveable[NDP]).
(DeviceRemoveable[NDP]).
Table 12-23. USB HC Rh Port2 Status Register
msb 0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
R
Reserved
PRSC
OCIC
PSSC PESC
CSC
W
RESET:
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31 lsb
R
Reserved
LSDA
PPS
Reserved
PRS
POCI
PSS
PES
CCS
W
RESET:
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Bits
Name
Description