Increasing control information from a single general purpose input/output (GPIO) mechanism

• US 20020161938A1
• Filed: 04/27/2001
• Published: 10/31/2002
• Est. Priority Date: 04/27/2001
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Bonomo, Ralph, Cromer, Daryl Carvis, Locker, Howard Jeffrey, Pennisi, Joseph Michael, Ward, James Peter
• Granted Patent: US 6,766,401 B2
• Time in Patent Office: Days
• US Class Current: 710/5
• CPC Class Codes: G06F 11/2247 Verification or detection of system hardware configuration

Abstract

Aspects for increasing control information from a single general purpose input/output (GPIO) mechanism are described. The aspects include establishing a plurality of voltage levels to indicate a plurality of states for association with installed options on a computer system planar. Further included is the determination of which of the installed options is present via the single GPIO.

Claims

1. A method for increasing control information from a single general purpose input/output (GPIO) mechanism, the method comprising:

establishing a plurality of voltage levels to indicate a plurality of states for association with installed options on a computer system planar; and

determining which of the installed options is present via a single GPIO.

2. The method of claim 1 wherein determining further comprises utilizing an analog-to-digital (A/D) converter with the GPIO for converting a voltage signal from the GPIO, wherein an output level of the A/D converter represents one of the plurality of states.

3. The method of claim 2 wherein determining further comprises reading the output level of the A/D by a POST (power-on self-test) routine.

4. The method of claim 2 wherein utilizing an A/D converter further comprises utilizing an unused A/D converter in the computer system.

5. The method of claim 4 further comprising utilizing an unused A/D converter of an environmental monitoring chip of the computer system.

6. The method of claim 1 wherein determining a plurality of states further comprises determining how many options are installed in the computer system.

7. The method of claim 1 wherein establishing a plurality of voltage levels further comprises utilizing a resistor network comprising a plurality of parallel resistors.

8. A system for increasing control information from a single general purpose input/output (GPIO) mechanism, the system comprising:

a computer system planar;

a single GPIO means coupled to the computer system planar; and

an analog-to-digital (A/D) converter coupled to the single GPIO means, the A/D converter converting a voltage level signal from the single GPIO means indicative of installed options on the computer system planar.

9. The system of claim 8 further comprising a controller coupled to the computer system planar to perform a POST routine and detect an output signal from the A/D converter.

10. The system of claim 9 wherein the A/D converter further comprises an unused A/D converter of an environmental monitoring chip coupled to the computer system planar.

11. The system of claim 9 wherein the output signal represents one of a plurality of states.

12. The system of claim 11 wherein each of the plurality of states represents presence of one of the installed options.

13. The system of claim 12 further comprising a resistor network coupled to the GPIO means for establishing voltage levels associated with each of the installed options.

14. The system of claim 13 wherein the resistor network comprises a plurality of resistors in parallel.

16. The method of claim 15 wherein utilizing a resistor network further comprises providing a plurality of resistors in parallel.

17. The method of claim 16 further comprising utilizing an unused A/D converter of an environmental monitoring chip of the computer system planar to convert the voltage signal level.

18. The method of claim 17 further comprising detecting the plurality of states during a POST (power-on self test) routine.

15. A method to allow determination of a plurality of states from a single signal line, the method comprising:

providing a single GPIO (general purpose input/output) mechanism on a computer system planar to detect status of at least one socket on the computer system planar; and

utilizing a resistor network on a signal line to the single GPIO mechanism to provide a voltage signal level indicative of a plurality of states for use in detecting which options are installed on the computer system planar.