
Agere Systems Inc.
169
Data Sheet
July 2001
T8302 Internet Protocol Telephone
Advanced RISC Machine (
ARM
)
13 USB Host Controller
(continued)
13.3.5 Hc Interrupt Enable Register
Each enable bit in the
Hc interrupt enable register
corresponds to an associated interrupt bit in the
Hc interrupt status register
. The
Hc interrupt enable register
is used to control which events generate a hard-
ware interrupt. When a bit is set in the
Hc interrupt status register
and the corresponding bit in the
Hc interrupt
enable register
is set
and
the
MIE
bit is set, then a hardware interrupt is requested on the host bus.
Writing a 1 to a bit in this register sets the corresponding bit, whereas writing a 0 to a bit in this register leaves the
corresponding bit unchanged. On read, the current value of this register is returned.
Table 149
.
Hc Interrupt Enable
Register
Address 0xE000 7010
6
5
RHSC
FNO
Read/Write
HCD
HC
R/W
R
Master interrupt enable. A 0 written to this field is ignored by HC.
A 1 written to this field enables interrupt generation due to events
specified in the other bits of this register. This is used by HCD as
a master interrupt enable.
R/W
R
Ownership change.
Bit #
Name
Bit #
31
MIE
Key
30
OC
29:7
RSVD
4
3
2
1
0
UE
RD
Description
SF
WDH
SO
Reset
31
MIE
0b
30
OC
0b
If 0 = Ignore.
If 1 = Enable interrupt generation due to ownership change.
Reserved.
Root hub status change.
29:7
6
RSVD
RHSC
—
0b
—
R/W
—
R
0 = Ignore.
1 = Enable interrupt generation due to root hub status change.
Frame number overflow.
5
FNO
0b
R/W
R
If 0 = Ignore.
If 1 = Enable interrupt generation due to frame number overflow.
Unrecoverable error.
4
UE
0b
R/W
R
If 0 = Ignore.
If 1 = Enable interrupt generation due to unrecoverable error.
Resume detect.
3
RD
0b
R/W
R
If 0 = Ignore.
If 1 = Enable interrupt generation due to resume detect.
Start of frame.
2
SF
0b
R/W
R
If 0 = Ignore.
If 1 = Enable interrupt generation due to start of frame.
Writeback done head.
1
WDH
0b
R/W
R
If 0 = Ignore.
If 1 = Enable interrupt generation due to HcDoneHead writeback.
Scheduling overrun.
0
SO
0b
R/W
R
If 0 = Ignore.
If 1 = Enable interrupt generation due to scheduling overrun.