Hot pluggins in a PCI bus system

• US 6,529,987 B1
• Filed: 09/08/1999
• Issued: 03/04/2003
• Est. Priority Date: 09/08/1999
• Status: Expired due to Term

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Reid, Eddie M.
• Primary Examiner(s): THAI, XUAN MARIAN
• Application Number:
  US09/392,348
• Time in Patent Office: 1,273 Days
• Field of Search: 710/300, 710/301, 710/302, 710/119, 710/313, 710/305, 710/306, 710/311, 710/312, 710/314, 714/5, 709/200, 709/253
• US Class Current: 710/302
• CPC Class Codes: G06F 13/4081 Live connection to bus, e.g. hot-plugging current or voltage limitation during live insertion H02H9/004
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

A hot-plug capable PCI bus system has only one slot coupled to each PCI bus. A bridge controller monitors and de-activates a particular PCI bus connected to the selected hot-plug slot being serviced for hot-plug operation.

Claims

1. A hot-plug capable PCI bus system, comprising:

hot-plug slots operating to interface the PCI bus system with external devices, each hot-plug slot including interface pins;

PCI buses;

sets of drivers corresponding to each of the PCI buses, each set of drivers to connect one PCI bus to one hot-plug slot; and

a controller coupled to said PCI buses and configured to deactivate a selected PCI bus connected to a slot engaged in a hot-plug operation, said controller operating to cause the drivers to drive the interface pins of the slot to a ground state and interrupt power to the slot during the hot-plug operation.

2. The system of claim 1, further comprising:

an under-voltage and an over-voltage detection circuit to generate corresponding under and over-voltage signals; and

an over-current detection circuit coupled to said hot-plug slots, said detection circuit configured to detect an amount of current flowing into each of the hot-plug slots.

3. The system of claim 2, further comprising:

a reference voltage used by said over-current detection circuit to generate an over-current signal.

4. The system of claim 2, further comprising:

reference voltages used by said under and over-voltage detection circuit; and

a comparator operating to compare said reference voltages with said under and over-voltage signals generated by said detection circuit.

5. The system of claim 1, further comprising:

a power supply having supply voltages, said power supply configured to supply power to the hot-plug slots; and

power switches for connecting said supply voltages to the hot-plug slots.

6. The system of claim 5, wherein the controller controls a slew rate of the power supply by regulating switching durations of the power switches.

7. The system of claim 5, wherein the controller controls a slew rate of the power supply by slowly adjusting the slew rate to prevent excessive current draw.

8. The system of claim 1, wherein said PCI buses include enhancements made to the buses.

9. A hot-plug PCI bus system, comprising:

PCI local buses;

sets of drivers corresponding to each of the PCI local buses;

adapter card slots, each PCI local bus connected to only one slot through a corresponding set of drivers, said slots capable of receiving an adapter card, of said adapter card slot including interface pins; and

a hot-plug bridge controller configured to control data being channeled through said PCI local buses, the controller operating to cause the drivers to control the interface pins of the slots between an energized state and a ground state and to control power to each of the slots.

10. The system of claim 9, wherein said PCI local buses send and receive data between a host interface bus and the adapter card.

11. The system of claim 9, wherein said hot-plug bridge controller is configured to selectively disconnect data channeling between a host interface bus and a selected adapter card slot.

12. The system of claim 9, wherein said hot-plug bridge controller enables hot-plug removal and insertion of the adapter card to and from the selected adapter card slot.

13. The system of claim 9, further comprising:

attention indicators associated with respective adapter card slots to indicate the states of hot-plug operation of the slots.

14. The system of claim 9, further comprising:

supply voltages powering each of said adapter card slots.

15. The system of claim 14, further comprising:

power isolation devices operating to connect said supply voltages to each slot of said adapter card slots.

16. A method for removing an adapter card from a selected hot-plug slot during hot-plug operation of a PCI bus, the method comprising:

receiving a request for removal of the adapter card;

in response to the request, quieting activity to the adapter card;

resetting the adapter card;

electrically disconnecting said adapter card from a power supply and the PCI bus;

forcing PCI bus interface pins to a ground state; and

after said forcing, removing the adapter card from the selected hot-plug slot.

17. The method of claim 16, wherein electrically disconnecting said adapter card includes de-activating pins to power switches.

18. The method of claim 16, wherein said de-activating PCI bus interface pins includes driving all PCI interface pins to ground level voltages.

19. The method of claim 16, further comprising:

driving an attention indicator for the selected hot-plug slot to indicate that the hot-plug slot is off.

20. A method for inserting an adapter card to a selected hot-plug slot during hot-plug operation of a PCI bus, the method comprising:

holding PCI interface pins at a ground state;

inserting the adapter card to the selected hot-plug slot while holding the PCI interface pins at the ground state;

receiving a power on request;

in response to the power on request, electrically connecting power to the adapter card;

pulsing a reset signal corresponding to the selected hot-plug slot; and

re-activating the PCI bus interface pins.

21. The method of claim 20, further comprising:

holding PCI interface pins below 0.7 volts before electrically connecting power to the adapter card.

22. The method of claim 20, further comprising:

driving attention indicator for the selected hot-plug slot to indicate that the hot-plug slot is on; and

configuring the adapter card for normal operation when the attention indicator indicates that the hot-plug slot is on.

23. A computer program, residing on a computer readable medium, for hot-plug removal of an adapter card from a selected hot-plug slot during hot-plug operation of a PCI bus, the program comprising executable instructions that enable the computer to:

receive a request for removal of the adapter card;

in response to the request, quiet activity to the adapter card;

reset the adapter card;

electrically disconnect said adapter card from a power supply and the PCI bus; and

force PCI bus interface pins to a ground state during removal of the adapter card.

24. A computer program, residing on a computer readable medium, for hot-plug insertion of an adapter card to a selected hot-plug slot, the program comprising executable instructions that enable the computer to:

hold PCI bus interface pins at a ground state;

receive a power on request;

in response to the power on request, electrically connect power to the adapter card;

pulse a reset signal corresponding to the selected hot-plug slot; and

re-activate the PCI bus interface pins.

25. A multiprocessor system comprising:

a memory device configured to store data;

processors coupled to the memory device and operating to process the data; and

a hot-plug bus system coupled to said processors, said bus system including;

local buses and hot-plug slots, each hot-plug slot including interface pins and capable of receiving an adapter card and enabling hot-plug operation, said hot-plug slot connecting to only one local bus;

sets of drivers corresponding to each of the local buses, each set of drivers to connect one local bus to one hot-plug slot;

a host bus configured to channel data between the processors and the hot-plug bus system;

a controller coupled to said host bus and said local buses, said controller configured to deactivate a selected local bus connected to a hot-plug slot engaged in a hot-plug operation, said controller operating to cause the drivers to drive the interface pins of the slot to a ground state interrupt power to the slot; and

external devices configured to send and receive data through the hot-plug bus system.

26. The system of claim 25, wherein the multiprocessor system is a network server system.