Distinguishing circuit

1. Technical Field

The present disclosure relates to a distinguishing circuit for a BIOS (Basic Input Output System) chip.

2. Description of Related Art

When designers design a computer system, a plurality of computer systems with different peripheral devices are designed simultaneously. For example, a first type of computer system will include an optical disk drive, and a second type of computer system will include a floppy disk drive. The other components of the first and second types of computer systems may be the same. As a result, programs loaded in BIOS chips in the first and second types of computer systems will be different.

In current computer system, the BIOS chip reads signals Chassis_ID 1 and Chassis_ID 2 to distinguish the first and second types of computer systems. Referring to FIG. 2 , a distinguishing circuit includes four resistors R 1 , R 2 , R 3 , and R 4 . A 3 volt power supply +3V is grounded through the resistors R 1 and R 2 connected in series. The 3 volt power supply +3V is further grounded through the resistors R 3 and R 4 connected in series. A node between the resistors R 1 and R 2 is connected to a BIOS chip 100 for outputting the signal Chassis_ID 1 . A node between the resistors R 3 and R 4 is also connected to the BIOS chip 100 for outputting the signal Chassis_ID 2 .

When the computer system is the Chassis ID 1 type, the resistors R 2 and R 3 are taken off. At this time, the signal Chassis_ID 1 is received by the BIOS chip 100 at a high level, and the signal Chassis_ID 2 is received by the BIOS chip 100 at a low level. The BIOS chip 100 determines that the computer system is the first type (Chassis ID 1 ), and loads corresponding programs. When the computer system is the second type (Chassis ID 2 ), the resistors R 1 and R 4 are taken off. At this time, the signal Chassis_ID 1 received by the BIOS chip 100 is at a low level, and the signal Chassis_ID 2 received by the BIOS chip 100 is at a high level. The BIOS chip 100 determines that the computer system is the second type, and loads corresponding programs.

The distinguishing circuit of related art, as described above, requires designers to design different motherboards to meet different types of computer systems. This is inconvenient.

Many aspects of the embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.

FIG. 1 is a circuit diagram of an exemplary embodiment of a distinguishing circuit.

FIG. 2 is a circuit diagram of a conventional distinguishing circuit.

The disclosure, including the accompanying drawings, is illustrated by way of examples and not by way of limitation. It should be noted that references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean at least one.

Referring to FIG. 1 , an exemplary embodiment of a distinguishing circuit includes five resistors R 11 , R 12 , R 13 , R 14 , and R 15 , and a front panel (F_Panel) connector 11 .

A first pin 1 of the front panel connector 11 is connected to a 3 volts power supply +3V from a motherboard through the resistor R 11 . A second pin 2 of the front panel connector 11 is connected to a first light LED 1 . A third pin 3 of the front panel connector 11 is connected to a hard disk drive light HDD_LED. A fourth pin 4 of the front panel connector 11 is connected to a second light LED 2 . A fifth pin 5 of the front panel connector 11 is grounded. A sixth pin 6 of the front panel connector 11 is connected to the 3 volts power supply +3V through the resistor R 12 . The sixth pin 6 is further connected to a power button PWRBTN. A seventh pin 7 of the front panel connector 11 is connected to the 3 volts power supply +3V through the resistor R 13 . An eighth pin 8 of the front panel connector 11 is connected to the 3 volts power supply +3V through the resistor R 14 . The eighth pin 8 is also connected to a BIOS chip 20 for outputting a signal Chassis_ID 1 to the BIOS chip 20 . A ninth pin 9 of the front panel connector 11 is connected to the 3 volts power supply +3V through the resistor R 15 . The ninth pin 9 is also connected to the BIOS chip 20 for outputting a signal Chassis_ID 2 to the BIOS chip 20 . A tenth pin 10 of the front panel connector 11 is grounded.

In this embodiment, when the signal Chassis_ID 1 is at a high level, and the signal Chassis_ID 2 is at a low level, the BIOS chip 20 determines that the computer system is a first type. When the signal Chassis_ID 1 is at a low level, and the signal Chassis_ID 2 is at a high level, the BIOS chip 20 determines that the computer system is a second type.

Therefore, when the computer system is the first type, the ninth pin 9 and the tenth pin 10 of the front panel connector 11 may be connected together through a jumper 30 . At this time, the signal Chassis_ID 1 received by the BIOS chip 20 is at a high level, and the signal Chassis_ID 2 received by the BIOS chip 20 is at a low level. The BIOS chip 20 will determine that the computer system is the first type. When the computer system is the second type, the eighth pin 8 and the tenth pin 10 of the front panel connector 11 may be connected together through the jumper 30 . At this time, the signal Chassis_ID 1 received by the BIOS chip 20 is at a low level, and the signal Chassis_ID 2 received by the BIOS chip 20 is at a high level. The BIOS chip 20 will determine that the computer system is the second type.

The distinguishing circuit can make the BIOS chip 20 distinguish between different types of computer systems by means of the jumper 30 . Compared with the conventional distinguishing circuit, the distinguishing circuit in this embodiment is far more convenient.

The foregoing description of the exemplary embodiments of the disclosure has been presented only for the purposes of illustration and description and is not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Many modifications and variations are possible in light of everything above. The embodiments were chosen and described in order to explain the principles of the disclosure and their practical application so as to enable others of ordinary skill in the art to utilize the disclosure and various embodiments and with such various modifications as are suited to the particular use contemplated. Alternative embodiments will become apparent to those of ordinary skills in the art to which the present disclosure pertains without departing from its spirit and scope. Accordingly, the scope of the present disclosure is defined by the appended claims rather than by the foregoing description and the exemplary embodiments described therein.