Motherboard Resources

2.3 Soft-Off Control

The motherboard design uses Soft-off control implemented under the SMM code in the BIOS. Any power supply used with the AP440FX motherboard must support the Soft-off feature. The ONCTL# pin of the I/O controller is connected to the Soft-off control line in the power supply circuit. The registers in the I/O controller that set the I/O address and control the ONCTL# pin are not setup until the SMM code is activated.

2.4 PCI Configuration Space Map

Table 30. PCI Configuration Space Map

Bus Number (hex)

Dev Number (hex)

Function Number (hex)

Description

00

00

00

00

00

00

00

00

00

07

07

07

08

13

11

0B

00

00

01

02

00

00

00

00

Intel 82440FX (PMC) Host Bridge

Intel 82371SB (PIIX3 ) ISA bridge

Intel 82371SB (PIIX3 ) IDE Controller

Intel 82371SB (PIIX3) USB

Video Controller

PCI Expansion Slot: user available

PCI Expansion Slot: user available

PCI Expansion Slot: Optional PCI Expansion Slot for 3 slot Riser

2.5 DMA Channels

Table 31. DMA Channels

DMA

0

1

2

3

4

5

6

7

Data Width

8- or 16-bits

8- or 16-bits

8- or 16-bits

8- or 16-bits

16-bits

16-bits

16-bits

Resource

Open

Audio

Floppy

Parallel Port (for ECP/EPP Config.)

Reserved - Cascade channel

Open

Open

Open

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Intel AP440FX specifications Soft-Off Control, PCI Configuration Space Map, DMA Channels

AP440FX specifications

The Intel AP440FX is a pivotal motherboard that was released in the late 1990s, designed to support the Intel Pentium II and Pentium III processors. Known for its robust performance and versatile functionalities, the AP440FX became a popular choice among computer enthusiasts and system builders during its time.

One of the defining features of the Intel AP440FX is its support for the Intel 440FX chipset. This chipset provided improved system performance through its use of a 66 MHz front-side bus, which allowed for faster data transfer between the CPU and the memory. The motherboard was equipped with two DIMM slots capable of supporting a maximum of 512 MB of SDRAM, providing users with the flexibility to choose the amount of memory they required for their applications.

Another notable characteristic of the AP440FX motherboard is its integrated support for various peripheral interfaces. It comes equipped with multiple ISA and PCI slots, allowing users to expand their system capabilities through the addition of various cards. The presence of two USB ports, which were relatively new at the time of its release, gave users access to a wider range of peripherals and external devices.

The Intel AP440FX also features an integrated IDE controller, enabling connection for hard drives and optical drives without the need for additional controller cards. This integrated solution simplified storage management for users and contributed to the overall efficiency of the system. The motherboard also supported SCSI through optional daughter cards, catering to users who required high-speed data transfer and reliable disk storage solutions.

Moreover, the AP440FX was designed with future upgrades in mind. Its BIOS supported plug-and-play installations, allowing users to easily configure new hardware components without extensive troubleshooting. Additionally, the ATX form factor of the motherboard contributed to its compatibility with a wide range of cases and power supplies.

In terms of power management, the Intel AP440FX incorporated advanced features such as ACPI (Advanced Configuration and Power Interface), which allowed for better power efficiency and management of power states. This feature was particularly beneficial for users looking to reduce energy consumption and improve the overall longevity of their systems.

All in all, the Intel AP440FX represented a significant advancement in motherboard technology during its era. Its combination of robust performance, upgradeability, and support for new technologies made it a popular choice for users looking to build powerful and efficient computing systems.