Field Name Bits Default Description
Port Owner 13 1b This bit unconditionally goes to a 0b when the Configured bit in the
CONFIGFLAG register makes a 0b to 1b transition. This bit
unconditionally goes to 1b whenever the Configured bit is zero.
System software uses this field to release ownership of the port to a
selected host controller (in the event that the attached device is not a
high-speed device). Software writes a one to this bit when the attached
device is not a high-speed device. A one in this bit means that a
companion host controller owns and controls the port.
Port Indicator
Control
15:14 00b Writing to this bit has no effect if the P_INDICATOR bit in the
HCSPARAMS register is a zero. If P_INDICATOR bit is a one, then the bit
encodings are:
Bit Value Meaning
00b Port indicators are off
01b Amber
10b Green
11b Undefined
Refer to the USB Specification Revision 2.0 for a description on how
these bits are to be used. This field is zero if Port Power is zero.
Port Test Control 19:16 0000b When this field is zero, the port is NOT operating in a test mode. A non-
zero value indicates that it is operating in test mode and the specific test
mode is indicated by the specific value. The encoding of the test mode
bits are (0110b - 1111b are reserved):
Bits Test Mode
0000b Test mode not enabled
0001b Test J_STATE
0010b Test K_STATE
0011b Test SE0_NAK
0100b Test Packet
0101b Test FORCE_ENABLE
Wake on Connect
Enable
20 0b Writing this bit to a one enables the port to be sensitive to device
connects as wake-up events. This field is zero if Port Power is zero.
Wake on
Disconnect
Enable
21 0b Writing this bit to a one enables the port to be sensitive to device
disconnects as wake-up events. This field is zero if Port Power is zero.
Wake on Over-
current Enable
22 0b Writing this bit to a one enables the port to be sensitive to over-current
conditions as wake-up events. This field is zero if Port Power is zero.
Reserved 31:23 Reserved
Packet Buffer Threshold Values – RW - 32 bits - [EOR_Reg : EHCI_EOR + 84h] Field Name Bits Default Description
IN Threshold 7:0 10h The PCI transaction starts when threshold of internal FIFO for receive
packet is reached.
The value represents multiple of 8 bytes – 10h means 128 bytes. The
smallest acceptable value is 08h (64 bytes).
Reserved 15:8 Reserved
OUT Threshold 23:16 60h The transmit packet starts at UTMI interface when threshold of internal
FIFO for transmit packet is reached.
The value represents multiple of 8 bytes – 10h means 128 bytes. The
smallest acceptable value is 08h (64 bytes).
Reserved 31:24 Reserved