82801DB Datasheet, PDF (444/587 Pages) Intel Corporation – Intel 82801DB I/O Controller Hub 4 (ICH4)

EHCI Controller Registers (D29:F7)
12.2.2.9
PORTSC—Port N Status and Control Register
Offset:
Attribute:
Default Value:
Port 0 CAPLENGTH + 44–47h
Port 1 CAPLENGTH + 48–4Bh
Port 2 CAPLENGTH + 4C–4Fh
Port 3 CAPLENGTH + 50–53h
Port 4 CAPLENGTH + 54–57h
Port 5 CAPLENGTH + 58–5Bh
R/W, R/WC, RO
00003000h
Size:
32 bits
A host controller must implement one or more port registers. Software uses the N_Port information
from the Structural Parameters Register to determine how many ports need to be serviced. All ports
have the structure defined below. Software must not write to unreported Port Status and Control
Registers.
This register is in the suspend power well. It is only reset by hardware when the suspend power is
initially applied or in response to a host controller reset. The initial conditions of a port are:
• No device connected,
• Port disabled.
When a device is attached, the port state transitions to the attached state and system software will
process this as with any status change notification. Refer to Chapter 4 of the Enhanced Host
Controller Interface (EHCI) Specification for Universal Serial Bus for operational requirements
for how change events interact with port suspend mode.
Bit
31:23
22
21
20
19:16
Description
Reserved. These bits are reserved for future use and will return a value of 0s when read.
Wake on Over-current Enable (WKOC_E) — RW.
0 = Disable. (Default)
1 = Enable. Writing this bit to a 1 enables the setting of the PME Status bit in the Power
Management Control/Status Register (offset 54, bit 15) when the Over-current Active bit (bit 4
of this register) is set to 1.
Wake on Disconnect Enable (WKDSCNNT_E) — RW. Default = 0b.
0 = Disable. (Default)
1 = Enable. Writing this bit to a 1 enables the setting of the PME Status bit in the Power
Management Control/Status Register (offset 54, bit 15) when the Current Connect Status
changes from connected to disconnected (i.e., bit 0 of this register changes from 1 to 0).
Wake on Connect Enable (WKCNNT_E) — RW.
0 = Disable. (Default)
1 = Enable. Writing this bit to a 1 enables the setting of the PME Status bit in the Power
Management Control/Status Register (offset 54, bit 15) when the Current Connect Status
changes from disconnected to connected (i.e., bit 0 of this register changes from 0 to 1).
Port Test Control — RW. When this field is 0, 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. Refer to Universal Serial Bus (USB) Specification, Revision 2.0, Chapter 7 for details on each
test mode.
Bits
Test Mode
0000
0001
0010
0011
0100
0101
0110–1111
Test mode Not enabled (Default)
Test J_STATE
Test K_STATE
Test SE0_NAK
Test Packet
Test FORCE_ENABLE
Reserved
444
Intel^® 82801DB ICH4 Datasheet