southbridge

The southbridge or I/O ControllerHub (ICH) is a processor of a chipset designed in bridge architecture.

Unlike the northbridge, to which it is connected via a high-speed bus, the southbridge is responsible for controlling the drives, interfaces, buses and connected peripherals such as the keyboard and computer mouse.

Chipset in bridge architecture with northbridge and southbridge

This includes the serial and parallel interfaces, the infrared and BIOS interfaces, the COM ports and Line Printer Terminals( LPT), the Integrated Drive Electronics( IDE), PCI bus and PCIe as well as the USB interface, Firewire, modem and LAN interfaces. If an ISA slot is present, it is managed by the southbridge via the PCI/ISA bridge.