FW82801DBM S L6DN Intel, FW82801DBM S L6DN Datasheet - Page 223

• Manufacturer Part Number: FW82801DBM S L6DN
• Manufacturer: Intel

Specifications of FW82801DBM S L6DN

• Lead Free Status / RoHS Status: Not Compliant

Intel
®
82801DBM ICH4-M Datasheet
5.17.10.1.3 Debug Software
Enabling the Debug Port
There are two mutually exclusive conditions that debug software must address as part of its startup
processing:
Debug software can determine the current ‘initialized’ state of the EHCI by examining the
Configure Flag in the EHCI USB 2.0 Command Register. If this flag is set, then system software
has initialized the EHCI. Otherwise, the EHCI should not be considered initialized. Debug
software will initialize the debug port registers depending on the state the EHCI. However, before
this can be accomplished, debug software must determine which root USB port is designated as the
debug port.
2. The debug port controller sends a token packet consisting of:
3. After sending the token packet, the debug port controller waits for a response from the debug
4. If valid packet was received from the device that was one byte in length (indicating it was a
5. If valid packet was received from the device that was more than one byte in length (indicating
6. If no valid packet is received, then the debug port controller:
•
•
device.
If a response is received:
handshake packet), then the debug port controller:
it was a data packet), then the debug port controller:
The EHCI has been initialized by system software
The EHCI has not been initialized by system software
— SYNC
— TOKEN_PID_CNT field
— USB_ADDRESS_CNT field
— USB_ENDPOINT_CNT field
— 5-bit CRC field.
— The received PID is placed into the RECEIVED_PID_STS field
— Any subsequent bytes are placed into the DATA_BUFFER
— The DATA_LEN_CNT field is updated to show the number of bytes that were received
— Resets the ERROR_GOOD#_STS bit
— Sets the DONE_STS bit
— Transmits an ACK handshake packet
— Resets the ERROR_GOOD#_STS bit
— Sets the DONE_STS bit
— Sets the EXCEPTION_STS field to 001b
— Sets the ERROR_GOOD#_STS bit
— Sets the DONE_STS bit.
after the PID.
Functional Description
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