Detailed explanation of Motherboard South Bridge

South
bridge is a ball grid array in a core logic chipset on the motherboard.
The South Bridge is called ICH(I/O CONTROLLER HUB) on Intel boards but
is called the South Bridge on AMD boards.

The
Southbridge chipset handles all computer input/output functions, such as
serial, audio, USB, system bios, ISA bus, mass storage controllers,
power management.

MASS STORAGE CONTROLLERS: Mass storage controllers such as PATA/SATA allow for the attachment of hard drives.

SPI BUS: This serial bus is used for firmware (bios) storage access.

ISA
BUS: ISA BUS remains an integral part of the modern South Bridge, although
the contemporary South Bridge no longer has ISA BUS provision. This bus
creates a control path to the super input/output controller(SIO CHIP).

DMA CONTROLLERS: This section of the Southbridge provides access to the main memory unit without the CPU’s assistance.

POWER
MANAGEMENT (APM and ACPI): The APM and ACPI provide signaling for the
computer to sleep shut down, hibernate, or power on.

REAL-TIME CLOCK: The real-time clock provides a time account for the system.

INTERRUPT CONTROLLERS: This section provides an access route for other devices to access the central processing unit.