User`s manual

User’s Manual
AIMB-240 Series User’s Manual
21
1.6.7 USB 2.0
The ICH4 contains an Enhanced Host Controller Interface (EHCI) compliant host controller
that supports USB high-speed signaling. High-speed USB 2.0 allows data transfers up to
480Mb/s which is 40 times faster than full-speed USB. The ICH4 also contains three
Universal Host Controller Interface (UHCI) controllers that support USB full-speed and
low-speed signaling.
The ICH4 supports 6 USB 2.0 ports. All six USB ports are high-speed, full-speed, and
low-speed capable. ICH4’s port-routing logic determines whether a USB port is controlled
by one of the UHCI controllers or by the EHCI controller.
1.6.8 Realtek
TM
ALC655 supports 5.1CH AC97 Audio
The ALC655 is a 16-bit, full-duplex AC'97 Rev. 2.3 compatible six-channel audio CODEC
designed for PC multimedia systems, including host/soft audio and AMR/CNR-based
designs.
The ALC655 incorporates proprietary converter technology to meet performance
requirements for PC99/2001 systems. The ALC655 CODEC provides three pairs of stereo
outputs with 5-bit volume control, a mono output, and multiple stereo and mono inputs,
along with flexible mixing, gain, and mute functions to provide a complete integrated audio
solution for PCs.
The digital interface circuitry of the ALC655 CODEC operates from a 3.3V power supply for
use in notebook and PC applications. An integrated 50mW/20ohm headset audio amplifier
for Front-Out and Surround-Out, a 14.318MHz -> 24.576MHz PLL, and a PCBEEP
generator cut BOM costs. The ALC655 also supports S/PDIF input and output for easy
connection of PCs to consumer electronic products, such as AC3 decoders/speakers and
mini-disk devices.
The ALC655 CODEC supports host/soft audio from Intel ICHx chipsets as well as audio
controller-based VIA/SIS/ALI/AMD/nVIDIA/ATI chipsets. Bundled Windows series drivers
(98/ME/NT/2000/XP), EAX/Direct Sound 3D/ I3DL2/A3D compatible sound effect utilities
(supporting Karaoke, 26 types of environment sound emulation, 10-band equalizer), HRTF
3D positional audio and Sensaura
™
3DPA (optional) provide an excellent entertainment
package and game experience for PC users. In addition, the ALC655 is embedded with an
impedance sensing capability to detect when a device has been connected to input or
output jacks.