Method and apparatus for the remote programming of a power supply

• US 5,678,049 A
• Filed: 06/06/1994
• Issued: 10/14/1997
• Est. Priority Date: 06/06/1994
• Status: Expired due to Term

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Massie, Harold L.
• Primary Examiner(s): AUVE, GLENN ALLEN
• Application Number:
  US08/254,249
• Time in Patent Office: 1,226 Days
• Field of Search: 395/750, 395/281, 395/282, 364/483, 363/74, 365/226, 307/31, 307/35
• US Class Current: 713/340
• CPC Class Codes: G06F 1/26 Power supply means, e.g. regulation thereof for memories G11C
• CPC Class Codes: G06F 1/28 Supervision thereof, e.g. detecting power-supply failure by out of limits supervision

Abstract

A computer system that includes supply programming circuits for remotely programming a power supply such that minimum operating voltages are maintained. The computer system includes a power supply having a supply output line and a supply sense line. The power supply provides a supply voltage via the supply output line in response to a sense voltage received via the sense line. A first circuit that operates at the supply voltage is coupled to the supply output line. A first supply programming circuit is coupled to the first circuit, the supply output line and the sense line. The first supply programming circuit senses rises the supply voltage at the first circuit and adjusts the sense voltage in response to the sensed supply voltage at the first circuit. A second circuit is also coupled to the supply output line. A second supply programming circuit senses the supply voltage at the second circuit and adjusts the sense voltage in response to the sensed supply voltage at the second circuit. Only the supply programming circuit that senses the lowest supply voltage adjusts the sense voltage.

Claims

1. A computer system comprising:

a bus;

a power supply including a supply output for supplying a supply voltage, a sense input for receiving a sense voltage, and circuitry for adjusting the supply voltage in response to the sense voltage;

a supply output line coupled to the power output of the power supply for carrying the supply voltage;

a sense line coupled to the sense input of the power supply for carrying the sense voltage;

a first adapter card coupled to the bus and to the supply output line at a first position, the first adapter card including;

a first circuit coupled to receive the supply voltage from the supply output line;

a first supply programming circuit coupled to the sense line and coupled to sense the supply voltage received by the first circuit;

a second adapter card coupled to the bus and to the supply output line at a second position, the second adapter card including;

a second circuit coupled to receive the supply voltage from the supply output line; and

a second supply programming circuit coupled to the sense line and coupled to sense the supply voltage received by the second circuit, wherein a one of the first and second supply programming circuits that senses a lowest value of the supply voltage received by its respective circuit outputs the sense voltage.

2. The computer system of claim 1, wherein the first and second supply programming circuits adjust the sense voltage by sinking current.

3. The computer system of claim 1, wherein each of the first and second supply programming circuits includes:

an output circuit coupled to the sense line for adjusting the sense voltage; and

,

a voltage reference circuit coupled to the supply output line and the output circuit for making a comparison between a sensed supply voltage and an internal reference voltage, and for driving the output circuit in response to the comparison.

4. The computer system of claim 3, wherein each of the first and second supply programming circuit further includes:

an input circuit coupled between the supply output line and the voltage reference circuit, the input circuit for outputting a reference voltage in response to the sensed supply voltage, wherein the voltage reference circuit compares the reference voltage to the internal reference voltage.

5. The computer system of claim 4, wherein each input circuit includes a first resistor and a second resistor coupled in series between the supply output line and system ground, the reference voltage being output at a node between the first resistor and the second resistor.

6. The computer system of claim 5, wherein the second resistor is a variable resistive load having a resistance that is varied in response to a control signal.

7. The computer system of claim 6, wherein the control signal is provided by a processor.

8. The computer system of claim 3, wherein each output circuit comprises:

a transistor having a base coupled to the voltage reference circuit, a collector coupled to the sense line, and an emitter, wherein the sense voltage at the collector varies inversely with a base voltage driven by the voltage reference circuit.

9. The computer system of claim 3, wherein each output circuit comprises:

a first transistor having a base coupled to the voltage reference circuit, a collector, and an emitter, wherein a collector voltage of the first transistor varies inversely with a base voltage driven by the voltage reference circuit;

a second transistor having a base coupled to the collector of the first transistor, an emitter coupled to the sense line, and an emitter, wherein the sense voltage at the collector varies with the collector voltage of the first transistor.

10. The computer system of claim 1, wherein the first supply programming circuit shuts off if the second supply programming circuit adjusts the sense voltage.

11. The computer system of claim 1, wherein each of the first and second supply programming circuits includes a voltage reference circuit of higher precision than the power supply such that the supply voltage has operating margins determined by the voltage reference circuit.

12. The computer system of claim 1, wherein the first and second circuits are microprocessors.

13. A method for remotely programming a supply voltage of a power supply such that minimum operating voltages are maintained, the method comprising the steps of:

sensing of the supply voltage by a first supply programming circuit at a first position of a supply output line to produce a first sensed supply voltage;

sensing of the supply voltage by a second supply programming circuit at a second position of the supply output line to produce a second sensed supply voltage;

outputting a sense voltage by the first supply programming circuit if the first sensed supply voltage is less than the second sensed supply voltage;

outputting the sense voltage by the second supply programming circuit if the second sensed supply voltage is less than the first sensed supply voltage; and

,

adjusting the supply voltage by the power supply in response to the sense voltage.