NH82801GHM S L8YR Intel, NH82801GHM S L8YR Datasheet - Page 215

• Manufacturer Part Number: NH82801GHM S L8YR
• Manufacturer: Intel

Specifications of NH82801GHM S L8YR

• Lead Free Status / RoHS Status: Compliant

Functional Description
5.20.10.1
Table 5-49. Debug Port Behavior (Sheet 1 of 2)
Intel
®
ICH7 Family Datasheet
There are two operational modes for the USB debug port:
Behavioral Rules
Table 5-49
registers as well as bits in the associated Port Status and Control register.
Theory of Operation
1. Mode 1 is when the USB port is in a disabled state from the viewpoint of a standard
2. Mode 2 is when the host controller is running (i.e., host controller’s Run/Stop# bit
1. In both modes 1 and 2, the Debug Port controller must check for software
2. If the debug port is enabled by the debug driver, and the standard host controller
3. If the standard host controller driver suspends the USB port, then USB debug
4. The ENABLED_CNT bit in the debug register space is independent of the similar
OWNER_CNT
host controller driver. In Mode 1, the Debug Port controller is required to generate a
“keepalive” packets less than 2 ms apart to keep the attached debug device from
suspending. The keepalive packet should be a standalone 32-bit SYNC field.
is 1). In Mode 2, the normal transmission of SOF packets will keep the debug
device from suspending.
requested debug transactions at least every 125 microseconds.
driver resets the USB port, USB debug transactions are held off for the duration of
the reset and until after the first SOF is sent.
transactions are held off for the duration of the suspend/resume sequence and until
after the first SOF is sent.
port control bit in the associated Port Status and Control register.
0
1
1
1
1
shows the debug port behavior related to the state of bits in the debug
ENABLED_CT
X
0
1
1
1
Enable
Port
X
X
0
0
1
Run /
Stop
X
X
0
1
0
Suspend
X
X
X
X
0
Debug port is not being used.
Normal operation.
Debug port is not being used.
Normal operation.
Debug port in Mode 1. SYNC
keepalives sent plus debug
traffic
Debug port in Mode 2. SOF
(and only SOF) is sent as
keepalive. Debug traffic is
also sent. Note that no other
normal traffic is sent out this
port, because the port is not
enabled.
Invalid. Host controller driver
should not put the controller
into this state (enabled, not
running and not suspended).
Debug Port Behavior
215