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Intel
®
IXP45X and Intel
®
IXP46X Product Line of Network Processors—USB 2.0 Host Controller
Intel
®
IXP45X and Intel
®
IXP46X Product Line of Network Processors
Developer’s Manual
August 2006
486
Order Number: 306262-004US
— Host System Error bit is to a one.
— HCHalted bit is set to a one.
• If the Host System Error Enable bit in the USBINTR register is a one, then the host
controller will issue a hardware interrupt. This interrupt is not delayed to the next
summarizes the required actions taken on the
various host errors.
Note:
After a Host System Error, Software must reset the host controller via HCReset in the
USBCMD register before re-initializing and restarting the host controller.
9.15
EHCI Deviation
For the purposes a dual-role Host/Device controller with support for On-The-Go
applications, it is necessary to deviate from the EHCI specification. Device operation
and On-The-Go operation is not specified in the EHCI and thus the implementation
supported in this core is proprietary. The host mode operation of the core is near EHCI
compatible with few minor differences documented in this section.
The particulars of the deviations occur in the areas summarized here:
• Embedded Transaction Translator — Allows direct attachment of FS and LS devices
in host mode without the need for a companion controller.
• Device operation — In host mode the device operational registers are generally
disabled and thus device mode is mostly transparent when in host mode. However,
there are a couple exceptions documented in the following sections.
• Embedded design interface — This core does not support a PCI Interface and
therefore the PCI configuration registers described in the EHCI specification are not
applicable.
• On-The-Go Operation — This design includes an On-The-Go controller for Port #1.
9.15.1
Embedded Transaction Translator Function
The OTG controller supports directly connected full and low speed devices without
requiring a companion controller by including the capabilities of a USB 2.0 high speed
hub transaction translator. Although there is no separate Transaction Translator block in
Table 186.
Summary Behavior of EHCI Host Controller on Host System Errors
Cycle Type
Master Abort
Target Abort
Data Phase Parity
Frame list pointer fetch
(read)
siTD fetch (read)
Fatal
Fatal
Fatal
siTD status write-back
(write)
Fatal
Fatal
iTD fetch (read)
Fatal
Fatal
Fatal
iTD status write-back
(write)
Fatal
Fatal
qTD fetch (read)
Fatal
Fatal
Fatal
qHD status write-back
(write)
Fatal
Fatal
Data write
Fatal
Fatal
Data read
Fatal
Fatal
Fatal
†
Potentially, a host controller implementation could continue operation without a halt. However,
the recommended behavior is to halt the host controller.