User`s manual

MMGA Series CyberResearch
®
Motherboards
24 ©Copyright 2009 CyberResearch, Inc.
2.5.10 Intel
®
ICH9DO Serial Peripheral Interface (SPI) BIOS
The SPI is connected to an SPI BIOS chip. A licensed copy of AMI BIOS is preinstalled on
the SPI BIOS chip.
2.5.11 Intel
®
ICH9DO USB Controller
2.5.11.1 Intel
®
ICH9DO USB Controller Overview
The ICH9DO comprises six full/low speed USB controllers that support the standard
Universal Host Controller Interface (UHCI) Revision 1.1. Each controller supports two
USB devices ensuring up to twelve USB 1.1 devices can be connected to the MMGA.
The ICH9DO also comprises two high-speed Enhanced Host Controller Interface (EHCI)
controllers. Each EHCI controller supports six USB 2.0 devices ensuring twelve USB 2.0
devices can be connected to the MMGA. EHCI controllers facilitate data transfer speeds
of 480 Mbps
Port routing logic on the ICH9DO determines whether a UHCI or an EHCI controller
controls a USB port.
2.5.11.2 MMGA USB Implementation
All twelve of the Intel® ICH9DO USB ports are implemented on the MMGA. Four USB
ports (USB Port 1 to USB Port 4) are connected to four external connectors and eight USB
ports (USB Port 5 to USB Port 12) are connected to four 8-pin onboard pin-headers. See
Figure 1-13.