Port Status AndControl USB2 (PORTSC1) – Offset 480 - 001 - ID:834576 | Intel® 800 Series Chipset Family Platform Controller Hub (PCH), Volume 2

Intel® 800 Series Chipset Family Platform Controller Hub (PCH), Volume 2

ID	Date	Version	Classification
834576	10/10/2024	001	Public

Port Status AndControl USB2 (PORTSC1) – Offset 480

There are NumUSB2 USB2 PORTSC registers at offsets :
480h, 490h, ... (480h + (NumUSB2-1)*10h)
The USB PORTSC registers should be accessed via DW writes for any modification.
Byte Writes have unintended behavior.

Bit Range	Default	Access	Field Name and Description
31	0h	RW/1S	Warm Port Reset Bit (WPR) When software sets this bit to 1b, the Warm Reset sequence is enabled.
30	0h	RW/L	Device Removable Bit (DR) Device Removable Bit
29:28	0h	RO	Rsvd2 (RSVD2) Reserved
27	0h	RW/P	Wake on Over-current Enable (WOE) 0 = Disable. (Default) 1 = Enable. Writing this bit to a 1b enables the port to be sensitive to overcurrent conditions as system wake-up events.
26	0h	RW/P	Wake on Disconnect Enable (WDE) 0 = Disable. (Default) 1 = Enable. Writing this bit to a 1b enables the port to be sensitive to device disconnects as system wake-up events.
25	0h	RW/P	Wake on Connect Enable (WCE) 0 = Disable. (Default) 1 = Enable. Writing this bit to a 1b enables the port to be sensitive to device connects as system wake-up events.
24	0h	RO	Cold Attach Status (CAS) Cold Attach Status
23	0h	RW/1C	Port Config Error Change (CEC) Note: This register is sticky.
22	0h	RW/1C	Port Link State Change (PLC) 0 = No change 1 = Link Status Change
21	0h	RW/1C	Port Reset Change (PRC) This flag is set to ‘1’ due a '1' to '0' transition of Port Reset (PR), for example, when any reset processing on this port is complete. 0 = No change 1 = Reset Complete
20	0h	RW/1C	Over-current Change (OCC) The functionality of this bit is not dependent upon the port owner. Software clears this bit by writing a 1 to it. 0 = No change. (Default) 1 = There is a change to Overcurrent Active.
19	0h	RW/1C	Warm Port Reset Change (WRC) This bit is set when Warm Reset processing on this port completes. 0 = No change. (Default) 1 = Warm reset complete
18	0h	RW/1C	Port Enabled Disabled Change (PEC) 0 = No change. (Default) 1 = There is a change to PED bit.
17	0h	RW/1C	Connect Status Change (CSC) This flag indicates a change has occurred in the port’s Current Connect Status (CCS) or Cold Attach Status (CAS) bits. 0 = No change. (Default) 1 = There is a change to the CCS or CAS bit. The xHC sets this bit to 1b for all changes to the port device connect status, even if system software has not cleared an existing Connect Status Change. For example, the insertion status changes twice before system software has cleared the changed condition, root hub hardware will be “setting” an already-set bit (that is, the bit will remain 1b).
16	0h	RW	Port Link State Write Strobe (LWS) 0 = When 0b, write data in PLS field is ignored. (Default) 1 = When this bit is set to 1b on a write reference to this register, this flag enables writes to the PLS field. Reads to this bit return ‘0’.
15:14	0h	RW/P	Port Indicator Control (PIC) Note: This register is sticky.
13:10	0h	RO	Port Speed (PORTSPEED) A device attached to this port operates at a speed defined by the following codes: Value: Speed 0001b: Full-speed 0010b: Low speed 0011b: Highspeed All other values reserved. Refer to the eXtensible Host Controller Interface for Universal Serial Bus Specification for additional details.
9	1h	RW/P	Port Power (PP) Default value of 1. 0 = This port is in the powered-off state 1 = This port is in the powered-on state. This indicates that the port does have power.
8:5	5h	RW/P	Port Link State (PLS) This field is used to power manage the port and reflects its currentlink state.When the port is in the Enabled state, system software may set the link U-state by writing this field. System software may also write this field to force a Disabled to Disconnected state transition of the port. Write Value and Description 0: The link shall transition to a U0 state from any of the U-states. 2: USB 2.0 ports only. The link should transition to the U2 State. 3: The link shall transition to a U3 state from any of the U-states. This action selectively suspends the device connected to this port. While the Port LinkState = U3, the hub does not propagate downstream-directed traffic to this port, but the hub will respond to resume signaling from the port. 5: USB 3.0 ports only. If the port is in the Disabled state (PLS = Disabled, PP= 1), then the link shall transition to a RxDetect state and the port shall transition to the Disconnected state, else ignored. 15: USB 2.0 ports only. If the port is in the U3 state (PLS = U3), then the link shall remain in the U3 state and the port shall transition to the U3Exit substate, else ignored. All other values are ignored Read Value and Definition 0: Link is in the U0 State 1: Link is in the U1 State 2: Link is in the U2 State 3: Link is in the U3 State (Device Suspended) 4: Link is in the Disabled State 5:Link is in the RxDetect State 6:Link is in the Inactive State 7: Link is in the Polling State 8:Link is in the Recovery State 9: Link is in the Hot Reset State 10: Link is in the Compliance Mode State 11: Link is in the Test Mode State 12–14: Reserved 15: Link is in the Resume State
4	0h	RW/1S	Port Reset Bit (PR) When software writes a 1 to this bit (from a 0), the bus reset sequence as 1 = port in reset 0 = port not in reset
3	0h	RO	Over-current Active (OCA) 0 = This port does not have an overcurrent condition (Default) 1 = This port currently has an overcurrent condition. This bit will automatically transition from 1 to 0 when the overcurrent condition is removed. The PCH automatically disables the port when the overcurrent active bit is 1.
2	0h	RO	Rsvd1 (RSVD1) Reserved
1	0h	RW/1C	Port Enabled Disabled (PED) Ports can only be enabled by the host controller as a part of the reset and enable. Software cannot enable a port by writing a 1 to this bit. Ports can be disabled by either a fault condition (disconnect event or other fault condition) or by host software. The bit status does not change until the port state actually changes. There may be a delay in disabling or enabling a port due to other host controller and bus events. 0=disable 1=enable(default)
0	0h	RO	Current Connect Status (CCS) This value reflects the current state of the port, and may not correspond directly to the event that caused the Connect Status Change bit (Bit 1) to be set. 0=no device is present 1=device is present on port.