Example Port Routing State Machine; Port Owner Hand-Off State Machine - Intel IXP45X Developer's Manual

Intel
the EHCI controller. The companion HC stack detects the disconnect and acknowledges
as it would in an ordinary standalone implementation. Subsequent connects will be
detected by the EHCI port register and the process will repeat.
9.14.2.3

Example Port Routing State Machine

Figure 53, "Port Owner Hand-Off State Machine" on page 414
how the port ownership should be managed. The following sections describe the entry
conditions to each state.
Figure 53.

Port Owner Hand-Off State Machine

EHCI CF 0
9.14.2.3.1 EHCI HC Owner
Entry to this state occurs whenever one of the following events occur:
• When the EHCI HC's Configure Flag (CF) bit in the CONFIGFLAG register transitions
from a zero to a one. This signals the fact that the system has a host controller
driver for the EHCI HC and that all ports in the USB 2.0 host controller must default
route to the EHCI controller.
• When the port is owned by a companion HC and the device is disconnected from
the port. The EHCI port routing control logic is notified of the disconnect, and
returns port routing to the EHCI controller. The connection state of the companion
HC goes immediately to the disconnected state (with appropriate side effect to
connect change, enable and enable change). The companion HC driver will
acknowledge the disconnect by setting the connect status change bit to a zero. This
allows the companion HC's driver to interact with the port completely through the
disconnect process.
• When system software writes a zero to the PortOwner bit in the PORTSC register.
This allows software to take ownership of a port from a companion host controller.
When this occurs, the routing logic to the companion HC effectively signals a
disconnect to the companion HC's port status and control register.
9.14.2.3.2 Companion HC Owner
Entry to this state occurs whenever one of the following events occur:
• When the Port Owner field transitions from a zero to a one.
• When the HS-mode HC's Configure Flag (CF) is equal to zero.
On entry to this state, the routing logic allows the companion HC port register to detect
a device connect. Normal port enumeration proceeds.
® ®
Intel IXP45X and Intel IXP46X Product Line of Network Processors
Developer's Manual
414
® ®
IXP45X and Intel IXP46X Product Line of Network Processors—USB 2.0 Host Controller
1
EHCI
Owner
PortOwner .neq. 0
.AND.
EHCI .eq. 1
Companion
((PortOwner .eq. 0)
.OR.
Disconnect)
.AND.
EHCI CF .eq. 1
illustrates an example of
EHC1 CF = 0
Owner
B4471-01
August 2006
Order Number: 306262-004US