
Agere Systems Inc.
181
Data Sheet
July 2001
T8302 Internet Protocol Telephone
Advanced RISC Machine (
ARM
)
13 USB Host Controller
(continued)
13.6.3 Hc Rh Status Register
The
Hc Rh status register
is divided into two parts. The lower word of a DWORD represents the hub status field
and the upper word represents the hub status change field. Reserved bits should always be written 0.
Table 165
.
Hc Rh Status Register
Address 0xE000 7050
16
LPSC
Read/Write
HCD
HC
W
R
Clear remote wake-up enable, (write).
Bit #
Name
Bit #
31
30:18
RSVD
17
15
14:2
RSVD
Description
1
0
CRWE
Field
OCIC
DRWE
OCI
LPS
Root Hub
Reset
—
31
CRWE
Writing a 1 clears
DRWE
.
Writing a 0 has no effect.
Reserved.
Overcurrent indicator change. This bit is set by hardware when
a change has occurred to the
OCI
field of this register.
30:18
17
RSVD
CCIC
—
0b
—
R/W
—
R/W
The HCD clears this bit by writing a 1.
Writing a 0 has no effect.
Local power status change, (write). The root hub does not sup-
port the local power status feature; thus, this bit is always read
as 0.
16
LPSC
0b
R/W
R
(Write) set global power: in global power mode (
PSM
= 0), this
bit is written to 1 to turn on power to all ports (clear port power
status). In per-port power mode, it sets
PPS
only on ports
whose
PPCM
bit is not set.
Writing a 0 has no effect.
(Read) device remote wake-up enable.
This bit enables a
CSC
bit as a resume event, causing a USB suspend to USB resume
state transition and setting the resume detected interrupt.
15
DRWE
0b
R/W
R
0 =
CSC
is not a remote wake-up event.
1 =
CSC
is a remote wake-up event.
(Write) set remote wake-up enable: writing a 1 sets
DRWE
.
Writing a 0 has no effect.
Reserved.
Overcurrent indicator. This bit reports overcurrent conditions
when the global reporting is implemented.
14:2
1
RSVD
OCI
—
0b
—
R
—
R/W
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.
Local power status, (read). The root hub does not support the
local power status feature; thus, this bit is always read as 0.
0
LPS
0b
R/W
R
(Write) clear global power:
In global power mode (
PSM
= 0),
This bit is written to 1 to turn off power to all ports (clear
port
power status). In per-port power mode, it clears port power sta-
tus only on ports whose
PPCM
bit is not set.
Writing a 0 has no effect.