Hardware Reference
In-Depth Information
Table 14.5. USB Connector Pinouts for Mini and Micro A/B Connectors
Most motherboards have several USB header connectors built in. These are 10-pin connectors
supporting two USB ports. Normally your motherboard includes a USB header cable with external
connectors mounted on a bracket, but if you need extras, companies such as MonoPrice and Cables
To Go sell header cables that are compatible with standard USB header pins.
Figure 14.8
shows a
typical USB header cable set.
Figure 14.8. A typical USB header cable set; plug it into your motherboard to connect devices to
the additional onboard USB ports (if present).
USB conforms to Intel's PnP specification, including
hot-plugging
, which means that you can plug in
devices dynamically without powering down or rebooting the system. Simply plug in the device, and
the USB controller in the PC detects the device and automatically determines and allocates the
required resources and drivers. One advantage of an interface such as USB with older systems is that
it requires only a single IRQ from the system. Therefore, you can connect up to 127 devices, and they
