ISP1160
Embedded USB Host Controller
Philips Semiconductors
USBOperational
USBReset write
USBOperational write
USBReset write
USBOperational write
USBResume
USBReset
USBSuspend write
hardware or software
reset
USBResume write
or
remote wake-up
USBReset write
MGT947
USBSuspend
Fig 14. The ISP1160 HC’s USB states.
The USB states are reflected in the HostControllerFunctionalState field of the
HcControl register (01H to read, 81H to write), which is located at bits 7 and 6 of the
register.
The HCD can perform only the USB state transitions shown in Figure 14.
Remark: The Software Reset in Figure 14 is not caused by the HcSoftwareReset
command. It is caused by the HostControllerReset field of the HcCommandStatus
register (02H to read, 82H to write).
9.2 Generating USB traffic
USB traffic can be generated only when the ISP1160 USB HC is in the
USBOperational state. Therefore, the HCD must set the
HostControllerFunctionalState field of the HcControl register before generating USB
traffic.
A simplistic flow diagram showing when and how to generate USB traffic is shown in
Figure 15. For greater accuracy, refer to the Universal Serial Bus Specification
Rev. 2.0 for the USB protocol and the ISP1160 USB HC’s register usage.
9397 750 11371
© Koninklijke Philips Electronics N.V. 2003. All rights reserved.
Product data
Rev. 04 — 04 July 2003
17 of 88
NXP [ NXP ]
