System and method for processor dual voltage detection and over stress protection

• US 6,327,663 B2
• Filed: 10/21/1998
• Issued: 12/04/2001
• Est. Priority Date: 10/21/1998
• Status: Expired due to Term

• Current Assignee: GlobalFoundries, Inc.
• Original Assignee: Advanced Micro Devices, Inc.
• Inventors: Smith, Lance L., Isaac, Gerald G., Caldwell, Dervinn D., Brcich, Joseph A.
• Primary Examiner(s): Myers, Paul R.
• Application Number:
  US09/176,737
• Publication Number:
  US 20010001878A1
• Time in Patent Office: 1,140 Days
• Field of Search: 710/102, 710/103, 713/1, 713/100, 713/300-340, 770/104
• US Class Current: 713/300
• CPC Class Codes: G06F 1/26 Power supply means, e.g. regulation thereof for memories G11C

Abstract

Method and system for preventing electronic overstress during powering up a processor with voltage detection capabilities employing a mechanism for detecting the voltage requirements of the processor to be coupled into a motherboard and accordingly adjusts the power supply of the motherboard to the processor voltage requirements. The detection mechanism includes sensing of logic signals by sensing a voltage from one or more pins of the processor. Those pins are internally connected to ground or internally not connected thus facilitating sensing of logic signals prior to powering up the processor. The probed signals are used to control the power supplied to the processor by adjustment mechanisms applied to power regulator or programmable logic devices. Since the detection of the proper operating voltage requirements of the processor and the consequent adjustment of the voltage power to be supplied to the processor occur during the powering up of the processor, electrical over stress and potential damage of the processor are eliminated.

Claims

1. A processor comprising:

a first core powered by a first supply voltage;

a first input/output buffer coupled to said first core, said first input/output buffer powered by a second supply voltage different from said first power supply voltage;

a first pin adapted to indicate a first signal indicative of a value of each of said first supply voltage and said second supply voltage, wherein said first signal, in a first state, is indicative of a first voltage for said first supply voltage and a second voltage for said second supply voltage;

a second pin adapted to indicate a second signal indicative of a third voltage for said first supply voltage independent of said first signal; and

a third pin adapted to indicate a third signal indicative of a number of supply voltages required by said processor.

2. The processor as recited in claim 1 wherein each of said first pin, said second pin, and said third pin are internally either connected to a ground or not connected.

3. An apparatus comprising:

a voltage detection unit coupled to at least a first pin of a processor, wherein a first signal on said first pin is indicative of a value of each of a first supply voltage for a core section of said processor and a second supply voltage for an input/output buffer of said processor, said first supply voltage different from said second supply voltage, and wherein said first signal, in a first state, is indicative of a first voltage for said first supply voltage and a second voltage for said second supply voltage; and

a voltage control unit coupled to said voltage detection unit, wherein said voltage control unit is configured to selectively enable said first supply voltage and said second supply voltage, and wherein said voltage control unit is coupled to at least a second pin of said processor, wherein a second signal on said second pin is indicative of a number of supply voltages required by said processor, wherein said voltage control unit is configured to selectively enable said first supply voltage and said second supply voltage responsive to said second signal.

4. The apparatus as recited in claim 3 wherein said voltage detection unit is further coupled to a third pin of said processor, wherein a third signal on said third pin is indicative of a third voltage for said first supply voltage independent of said first signal.

5. The apparatus as recited in claim 4 wherein said voltage detection unit comprises a first resistor coupled between a first node and a ground and a second resistor coupled to said first node, and wherein said third pin is coupled to said first node.

6. The apparatus as recited in claim 5 wherein said second resistor is coupled to a second node to which a third resistor is also coupled, and wherein said first pin is coupled to said second node.

7. The apparatus as recited in claim 6 wherein said third resistor is coupled to a third node, and wherein a reference input of a voltage regulator circuit is coupled to said third node, and wherein said voltage detection unit further comprises a fourth resistor coupled to said third node and a fourth node, and wherein an output of said voltage regulator circuit is coupled to said fourth node, and wherein said fourth node is coupled to provide said first supply voltage to said processor.

8. The apparatus as recited in claim 7 wherein said voltage detection unit further comprises a fifth resistor coupled between a fifth node and said ground and a sixth resistor coupled to said fifth node, and wherein said first pin is coupled to said fifth node.

9. The apparatus as recited in claim 8 wherein said sixth resistor is coupled to a sixth node, and wherein a reference input of a second voltage regulator circuit is coupled to said sixth node, and wherein said voltage detection unit further comprises a seventh resistor coupled to said sixth node and a seventh node, and wherein an output of said second voltage regulator circuit is coupled to said seventh node, and wherein said seventh node is coupled to provide said second supply voltage to said processor.

10. A method comprising:

receiving a first signal from a first pin of a processor, said first signal indicative of a value of each of a first supply voltage for a core section of said processor and a second supply voltage for an input/output buffer of said processor, said first supply voltage different from said second supply voltage, wherein said first signal, in a first state, is indicative of a first voltage for said first supply voltage and a second voltage for said second supply voltage;

receiving a second signal on a second pin of said processor, said second signal indicative of said first supply voltage independent of said first signal;

adjusting said first supply voltage and said second supply voltage responsive to said first signal and said second signal; and

receiving a third signal on a third pin of said processor, said third signal indicative of a number of supply voltages required by said processor.