82NM10 Datasheet, PDF (179/671 Pages) Intel Corporation – Intel® NM10 Family Express Chipset

Functional Description
Chipset Process Error
The HC monitors certain critical fields during operation to ensure that it does not
process corrupted data structures. These include checking for a valid PID and verifying
that the MaxLength field is less than 1280. If it detects a condition that would indicate
that it is processing corrupted data structures, it immediately halts processing, sets the
HC Process Error bit in the HC Status register and signals a hardware interrupt to the
system.
This interrupt cannot be disabled through the Interrupt Enable register.
Host System Error
Chipset sets this bit to 1 when a Parity error, Master Abort, or Target Abort occur. When
this error occurs, Chipset clears the Run/Stop bit in the Command register to prevent
further execution of the scheduled TDs. This interrupt cannot be disabled through the
Interrupt Enable register.
5.18.7
USB Power Management
The Host controller can be put into a suspended state and its power can be removed.
This requires that certain bits of information are retained in the resume power plane of
Chipset so that a device on a port may wake the system. Such a device may be a fax-
modem, which will wake up the machine to receive a fax or take a voice message. The
settings of the following bits in I/O space will be maintained when Chipset enters the
S3, S4, or S5 states.
Table 5-72.Bits Maintained in Low Power States
Register
Offset
Bit
Description
Command
Status
Port Status and
Control
00h
02h
10h & 12h
3 Enter Global Suspend Mode (EGSM)
2 Resume Detect
2 Port Enabled/Disabled
6 Resume Detect
8 Low-speed Device Attached
12 Suspend
When Chipset detects a resume event on any of its ports, it sets the corresponding
USB_STS bit in ACPI space. If USB is enabled as a wake/break event, the system
wakes up and an SCI generated.
5.18.8
USB Legacy Keyboard Operation
When a USB keyboard is plugged into the system, and a standard keyboard is not, the
system may not boot, and MS-DOS legacy software will not run, because the keyboard
will not be identified. Chipset implements a series of trapping operations which will
snoop accesses that go to the keyboard controller, and put the expected data from the
USB keyboard into the keyboard controller.
Datasheet
179