GB2418749A

GB2418749A - Interfacing an AGP card with a PCI slot

Info

Publication number: GB2418749A
Application number: GB0421659A
Authority: GB
Inventors: Hsiao-Wen Hao; An-Sheng Chang
Original assignee: Giga Byte Technology Co Ltd
Current assignee: Giga Byte Technology Co Ltd
Priority date: 2004-09-29
Filing date: 2004-09-29
Publication date: 2006-04-05
Also published as: GB0421659D0

Abstract

A method for interfacing an Accelerated Graphics Port (AGP) card with a Peripheral Component Interface (PCI) slot on a motherboard comprises the motherboard scanning a number of PCI slots trying to detect the presence of an AGP card which is coupled to a PCI slot. If the AGP card is detected then it is used as the display graphics adaptor. The BIOS could be used to control the detection. If an AGP card is not present then a graphics adaptor which is built in to the motherboard could be used.

Description

24 1 8749

METHOD OF INTERFACING AGP CARD WITH PCI BUS SLOT

The present invention relates to a method of interfacing an AGP (Accelerated Graphics Port) card with a PCI (Peripheral Component Interconnect) bus slot, and to a computer having an AGP card inserted in and interfaced with a PCI bus slot on its motherboard.

Buses in prior art industry computers are classified as ISA (Industry Standard Architecture), VISA (Virtual Instrument Software Architecture), PCI and AGP types, for example. A plurality of slots are provided on a motherboard and interface cards are plugged into corresponding slots. The interface cards are connecting devices between peripherals and the peripherals are controlled by the motherboard through the interface cards.

Further, ISA slots in early days were superseded by VISA slots, and the VISA slots were then followed by PCI slots. Now, the PCI slots have been further developed, resulting in AGP slots.

Nowadays, although technologies are greatly improved, nevertheless some ISA slots and PCI slots are provided together on old motherboards.

Therefore, when ISA slots are all plugged with ISA interface cards, another ISA interface card cannot be plugged into any slot on the motherboard, and this is also the case with the PCI slots.

It is known to provide an interface card with two kinds of interface that can be plugged in to any PCI or ISA slots on the motherboard. The slot interfaces are not restricted to specific cards and therefore, the cost is lowered.

Referring to Fig. 1, a plurality of components 11 are provided on the interface card 10; further, first and second connecting interfaces 12, 13 are located on different edges of the interface card 10 and are compatible with peripheral component interconnect (PCI) and industry standard architecture (ISA) slots. The first and second connecting interfaces 12, 13 are connected to the components 11 by different conductors; further, a socket 14 is set on a further edge region of the interface card 10 to be connected with the first and second connecting interfaces 12, 13. Furthermore, a fixed plate 15 is mounted on the further edge region of the interface card 10 and includes an opening for accommodating the socket 14 (not shown).

However, an AGP interface card cannot be plugged into a motherboard with all PCI slots, because no AGP slots are provided on the motherboard.

] O Therefore, a new motherboard with AGP slots is needed.

The present invention (which is defined in the independent claims) provides a method for interfacing an AGP card with a PCI bus slot and

resolves drawbacks of prior art motherboards.

In one embodiment the method of the present invention provides: transmitting a detecting signal to a motherboard, scanning status of a plurality of PCI bus slots on the motherboard, and out-connecting an AGP card for displaying.

To provide a further understanding of the invention, the following detailed description illustrates embodiments and examples of the invention, this detailed description being provided only for illustration of the invention.

Fig. 1 shows a schematic diagram of a prior art interface card with PCI and ISA interfaces; Fig. 2 shows a flow diagram of a method in accordance with the invention for supplying an AGP card on a PCI bus slot in a computer.

Generally, displaying functions are provided in different ways. Firstly, the AGP displaying functions are provided by chips on the motherboard with built-in displaying functions. Such built-in displaying functions are usually utilized by portable computers for standard purposes. Secondly, an AGP card is needed for playing computer games with a high resolution smooth display quality, and for this purpose an AGP card is plugged into an AGP slot. The built-in displaying functions of the chips on the motherboard are insufficient for playing computer games.

The present invention provides a third method, involving inserting an AGP card in a PCI bus slot. Therefore, users can choose a display functionality provided either by the inserted AGP card or by the built-in display functionality of the motherboard when an AGPis not provided.

A low-cast motherboard has only PCI slots and chips with built-in displaying functions. The present invention enables an AGP card to be plugged into a PCI slot and to be interfaced therewith by mapping PCI signals to AGP signals. The defined bandwidth of PCI signals is narrower than AGP signals, but the pins for receiving AGP and PCI signals are the same although their layout is different. Moreover, AGP has a better performance than the Fig. 2 shows a flow diagram for supplying an AGP card on a PCI bus slot, and it provides the following steps: transmitting (S100) a detecting signal to a motherboard (eg from the BIOS of the computer, not shown) scanning the status of a plurality of PCI bus slots on the motherboard (S102); judging whether an AGP card is connected to the output of any PCI bus (S104), and mapping the signals of the PCI bus to the layout of an AGP bus. If the result produced by (S104) is positive, then the AGP card is used for displaying (S106); otherwise, a built-in display chip eg on the motherboard is for displaying (S108).

Prior art motherboards use different interface cards for different functions, but the described embodiment of the present invention interfaces a layout with PCI slots to the layout of an AGP slot. Therefore, PCI bus signals are transformed to AGP bus signals and then the AGP card can be plugged into the PCI slot of the motherboard.

There has thus been described a novel and unobvious PCI bus which eliminates or alleviates problems in the prior art. Furthermore, those skilled in the art will readily appreciate that the above description is only illustrative of a specific embodiment of the invention. The scope of the invention is defined by the claims.

Claims

1. A method of interfacing an AGP (Accelerated Graphics Port) card with a PCI (Peripheral Component Interconnect) bus slot on a motherboard, the method comprising: providing a detecting signal on the motherboard; in response to the detecting signal, scanning the status of a plurality of PCI bus slots on the motherboard to detect an AGP and inserted into a coupling the inserted AGP card to its associated PCI bus slot so as to generate a graphics display output.

2. A method as claimed in claim 1, wherein the detecting signal is provided by a basic inpuVoutput system (BIOS) of a computer.

3. A method as claimed in claim 1 or claim 2, wherein the step of scanning the status of a plurality of PCI bus slots on the motherboard includes determining whether an AGP card is connected to any PCI bus.

4. A method as claimed in claim 3, wherein if the result of determining whether an AGP card is connected to any PCI bus is positive, the connected AGP card is used for displaying; otherwise, a built-in displaying function of a chip on the motherboard is used for generating a graphics display output.

5. A method as claimed in any preceding claim, wherein the signals on the PCI bus are mapped onto a AGP bus layout.

6. A method of interfacing an AGP (Accelerated Graphics Port) card with a PCI (Peripheral Component Interconnect) bus slot, the method being substantially as described hereinabove with reference to Figure 2 of the accompanying drawings.

7. A computer having a motherboard with a PCI (Peripheral Component Interconnect) bus slot and an AGP (Accelerated Graphics Port) card inserted in and interfaced with the PCI bus slot to generate a graphics display of the computer.