Method for computer implemented hot-swap and hot-add

• US 6,418,492 B1
• Filed: 10/01/1997
• Issued: 07/09/2002
• Est. Priority Date: 05/13/1997
• Status: Expired due to Term

• Current Assignee: Round Rock Research LLC
• Original Assignee: Micron Electricals
• Inventors: Smith, Dennis H., Wallach, Walter A., Papa, Stephen E. J.
• Primary Examiner(s): Beausoleil, Robert
• Assistant Examiner(s): PHAN, RAYMOND NGAN
• Application Number:
  US08/941,970
• Time in Patent Office: 1,742 Days
• Field of Search: 395/281-283, 395/306-309, 395/284-285, 395/500, 345/308, 380/49
• US Class Current: 710/302
• CPC Class Codes: G06F 13/4027 using bus bridges G06F13/4022 takes precedence
• CPC Class Codes: G06F 13/4081 Live connection to bus, e.g. hot-plugging current or voltage limitation during live insertion H02H9/004

Abstract

Apparatus and method is disclosed for providing hot-add and hot swap capability to a computer system with a processor, and a memory, connected to a system bus. The apparatus includes a first bus, an adapter card slot, a switchable interface unit and hot-swap hot-add program code means. The first bus is connected to the system bus. The adapter card slot has a first port and a second port. The switchable interface unit includes a primary port and a secondary port. The primary port is connected to the first bus and the secondary port is connected to the first port of the adapter card slot. The switchable interface unit is responsive to a hot-swap hot-add power-down request to disconnect the second port from the first bus. The switchable interface unit is also responsive to a power-up request to reconnect the second port to the first bus. The hot-swap hot-add program code means in the memory accepts a request to connect a peripheral device adapter card into the second port of said adapter card slot, and responsive to the request communicates a power-down request to the switchable interface unit.

Claims

1. A method of hot adding an adapter to an operational computer having a primary bus and at least one secondary bus, the secondary bus being connected to the primary bus by a bus-to-bus bridge and the secondary bus being connected to one or more adapters, the method comprising:

selecting a range of addresses represented by an upper bound address and a lower bound address for the bus-to-bus bridge;

storing the upper bound address and the lower bound address in a control register in the bus-to-bus bridge; and

adding the adapter to the secondary bus such that the adapter is addressable by the operational computer within the selected range.

2. The method of claim 1, additionally comprising supplying power from the computer power supply to the adapter.

3. The method of claim 1, additionally comprising receiving a request in a hot plug program for the hot add of the adapter, the request being generated by a user of the operational computer.

4. The method of claim 1, wherein the adapter is capable of connection to a PCI bus.

5. The method of claim 1, wherein the addresses are memory mapped input/output addresses.

6. The method of claim 1, wherein the addresses are memory addresses.

7. A method of configuring a computer having a primary bus that is connected to a plurality of bus-to-bus bridges for the hot add of an adapter, the method comprising:

selecting a range of bus numbers represented by a lower bound bus number and an upper bound bus number for each of the plurality of bus-to-bus bridges, the range of bus numbers being selected such that the bus numbers of the computer are sparsely allocated across each of the bus-to-bus bridges; and

storing the upper bound bus number and the lower bound bus number in each bus-to-bus bridge.

8. The method of claim 7, additionally comprising:

connecting a new secondary bus to one of the bus-to bus bridges; and

assigning an unused bus number within the selected range of bus numbers stored in the bus-to-bus bridge.

9. The method of claim 8, wherein the new secondary bus is on a canister.

10. The method of claim 8, wherein the new secondary bus is a PCI bus.

11. The method of claim 8, additionally comprising adding an adapter to a secondary bus that is connected to one of the bus-to-bus bridges.

12. A method of hot adding an adapter to an operational computer having a primary bus, a bus-to bus bridge connected to the primary bus, a secondary bus connected to the bus-to-bus bridge, and a plurality of bus slots connected to the secondary bus, the method comprising:

designating a first range of addresses represented by an upper bound address and a lower bound address to the bus-to-bus bridge;

disabling power to the secondary bus;

adding an adapter to a bus slot such that the adapter is addressable by the operational computer; and

enabling power to the secondary bus.

13. The method of claim 12, wherein the adapter is configured to communicate with a PCI bus.

14. The method of claim 12, additionally comprising storing the first range of addresses represented by the upper bound address and the lower bound address in a control register in the bus-to-bus bridge.

15. The method of claim 12, additionally comprising quiescing all signals on the bus after negotiating control of the bus.

16. The method of claim 12, wherein each of the addresses in the first range of addresses are memory addresses.

17. The method of claim 12, additionally comprising supplying power to the bus from the computer power supply.