Bus interface for IDE device

• US 5,920,709 A
• Filed: 11/18/1996
• Issued: 07/06/1999
• Est. Priority Date: 06/04/1996
• Status: Expired due to Fees

• Current Assignee: Exabyte Corporation (MidgardXXI, Inc.)
• Original Assignee: Exabyte Corporation (MidgardXXI, Inc.)
• Inventors: Marasch, Marek Joseph, Foxworthy, Neal, Hartung, Steven F., Bakeman, Jack S. Jr.
• Primary Examiner(s): Auve, Glenn A.
• Assistant Examiner(s): Thlang, Eric S.
• Application Number:
  US08/751,681
• Time in Patent Office: 960 Days
• Field of Search: 704/273, 395/653, 395/280, 395/309, 395/283, 395/306, 395/311
• US Class Current: 710/305
• CPC Class Codes: G06F 13/385 for adaptation of a particular data processing system to different peripheral devices

Abstract

An interface apparatus or Nest (30) fits into a peripheral slot (24) connected to an IDE bus (60) of a host computer. IDE devices, such as magnetic tape drives and hard drives, are hot swapable in and out of Nest (30) while the IDE bus is active. The Nest isolates the IDE device from the active IDE bus until such time (e.g., initialization of the IDE device) as connection of the IDE device to the IDE bus will not corrupt the IDE bus, after which time the Nest connects the IDE device to the IDE bus while the IDE bus is active. A nest driver (230) is executed for computer systems (200) which tend to establish a permanent inventory of IDE devices upon system boot-up. The nest driver determines whether a Nest is connected to the host; determines whether an IDE device has been inserted in the Nest; and determines when the IDE device in the Nest has been initialized. After device initialization, the nest driver (1) opens the Nest so that the IDE device is connected to the IDE bus and the Nest becomes transparent to the host; (2) queries the IDE device installed in the Nest to determine its device type, and thereafter (3) reenumerates a dynamic device database maintained by the operating system of the host.

Claims

1. An interface apparatus which fits into a peripheral slot of a host computer, the host computer having an IDE bus, the interface apparatus comprising:

an interface frame having an internal bay which accommodates an IDE device, the interface frame being insertable into the peripheral slot of the host computer;

an interface circuit which performs IDE communication with the host computer over the IDE bus when no IDE device is in the internal bay, the interface circuit also serving, while the IDE bus is active and while the IDE device is being inserted into the internal bay of the interface frame, to keep the IDE device isolated from the IDE bus until such time as connection of the IDE device to the IDE bus will not corrupt the IDE bus, after which time the circuit connects the IDE device to the IDE bus while the IDE bus is active;

wherein the interface circuit emulates a sequence of events that occur on the IDE bus for the IDE device that is inserted into the internal bay, and subsequently establishes a current state of the IDE bus in the IDE device.

2. The apparatus of claim 1, wherein the interface circuit keeps the IDE device isolated from the IDE bus until the IDE device has completed its own initialization.

3. The apparatus of claim 1, wherein the interface circuit is mounted on the interface frame.

4. The apparatus of claim 1, wherein the interface circuit comprises:

an insertion/removal detector which detects whether the IDE device is inserted into the bay of the interface frame;

a gate which selectively connects the IDE bus with the IDE device;

a set of registers for storing information indicative of a current state of the IDE bus; and

means for transferring the contents of the set of registers to the IDE device when the IDE bus is connected to the IDE device.

5. The apparatus of claim 1, wherein the interface circuit further comprises an initializer for initializing a master/slave status of the IDE device.

6. The apparatus of claim 1, wherein the interface circuit emulates an IDE device when no IDE device is in the internal bay.

7. A computer system comprising:

a microprocessor;

an IDE adapter connected to the microprocessor;

an IDE bus connected between the IDE adapter;

an interface apparatus connected to the IDE bus which performs IDE communication with the microprocessor over the IDE bus when no IDE device is connected to the interface apparatus, and when the interface apparatus has the IDE device connected thereto while the IDE bus is active, the interface apparatus keeps the IDE device isolated from the IDE bus while the IDE bus is active until such time as connection of the IDE device to the IDE bus will not corrupt the IDE bus, after which time the interface apparatus connects the newly connected IDE device to the IDE bus while the IDE bus is active;

wherein the interface circuit emulates a sequence of events that occur on the IDE bus for the IDE device that is inserted into the internal bay, and subsequently establishes a current state of the IDE bus in the IDE device.

8. The computer system of claim 7, wherein the interface apparatus keeps the IDE device isolated from the IDE bus until the IDE device has completed its own initialization.

9. The computer system of claim 7, wherein the interface apparatus further comprises an initializer for initializing a master/slave status of the IDE device.

10. The apparatus of claim 7, wherein the interface apparatus emulates an IDE device when no IDE device is connected to the interface apparatus.

11. A computer system comprising:

a microprocessor;

an IDE adapter connected to the microprocessor;

an IDE bus connected between the IDE adapter;

an interface apparatus connected to the IDE bus which performs IDE communication with the microprocessor over the IDE bus when no IDE device is connected to the interface apparatus, and when the interface apparatus has the IDE device connected thereto while the IDE bus is active, the interface apparatus keeps the IDE device isolated from the IDE bus while the IDE bus is active until such time as connection of the IDE device to the IDE bus will not corrupt the IDE bus, after which time the interface apparatus connects the newly connected IDE device to the IDE bus while the IDE bus is active;

wherein the interface apparatus comprises an interface frame having an internal bay which accommodates the IDE device, the interface frame being insertable into a peripheral slot of a housing of the host computer.

12. The computer system of claim 11, wherein the interface apparatus comprises:

an insertion/removal detector which detects whether the IDE device is inserted into the bay of the interface frame;

a gate which selectively connects the IDE bus with the IDE device;

a set of registers for storing information indicative of a current state of the IDE bus; and

means for transferring the contents of the set of registers to the IDE device when the IDE bus is connected to the IDE device.

13. A computer system comprising:

a microprocessor;

an IDE adapter connected to the microprocessor;

an IDE bus connected between the IDE adapter;

an interface apparatus connected to the IDE bus and to which an IDE device is connectable while the IDE bus is active, the interface apparatus serving to keep the IDE device isolated from the IDE bus while the IDE bus is active until such time as connection of the IDE device to the IDE bus will not corrupt the IDE bus, after which time the interface apparatus connects the newly connected IDE device to the IDE bus while the IDE bus is active;

wherein the microprocessor maintains a dynamic device database, and wherein the microprocessor executes a driver which causes reenumeration of the database to reflect

wherein the microprocessor maintains a dynamic device database, and wherein the microprocessor executes a driver which causes reenumeration of the database to reflect connection or disconnection of the IDE device relative to the interface apparatus while the IDE bus is active.

14. The computer system of claim 13, wherein the driver resides in and is executed in a first ring of an operating system of the microprocessor,

wherein the driver schedules execution of at least a portion of the driver in a second ring of the operating system for the purpose of removing, during a time of execution of the second ring, a node of the dynamic device database which is a parent to the IDE device which as been connected or disconnected to the interface apparatus, and

wherein the driver requests at least a partial inventory of the computer system during execution of the first ring in order to reenumerate the database.

15. An interface apparatus which fits into a peripheral slot of a host computer, the host computer having an IDE bus, the interface apparatus comprising:

an interface frame having an internal bay which accommodates an IDE device, the interface frame being insertable into the peripheral slot of the host computer;

an interface circuit which, while the IDE bus is active and while the IDE device is being inserted into the internal bay of the interface frame, keeps the IDE device isolated from the IDE bus until a predetermined electrical condition of the IDE device is sensed;

wherein the predetermined electrical condition of the IDE device is sensed by sensing a predetermined signal issued by the IDE device.

16. The apparatus of claim 15, wherein the interface circuit is mounted on the interface frame.

17. The apparatus of claim 15, wherein the interface circuit comprises:

an insertion/removal detector which detects whether the IDE device is inserted into the bay of the interface frame;

a gate which selectively connects the IDE bus with the IDE device;

a set of registers for storing information indicative of a current state of the IDE bus; and

means for transferring the contents of the set of registers to the IDE device when the IDE bus is connected to the IDE device.

18. The apparatus of claim 15, wherein the interface circuit further comprises an initializer for initializing a master/slave status of the IDE device.

19. An interface apparatus which fits into a peripheral slot of a host computer, the host computer having an IDE bus, the interface apparatus comprising:

an interface frame having an internal bay which accommodates an IDE device, the interface frame being insertable into the peripheral slot of the host computer;

an interface circuit which, while the IDE bus is active and while the IDE device is being inserted into the internal bay of the interface frame, keeps the IDE device isolated from the IDE bus until a predetermined electrical condition of the IDE device is sensed;

wherein the predetermined electrical condition of the IDE device is sensed by reading a task file of the IDE device.

20. The apparatus of claim 19, wherein the interface circuit is mounted on the interface frame.

21. The apparatus of claim 19, wherein the interface circuit comprises:

an insertion/removal detector which detects whether the IDE device is inserted into the bay of the interface frame;

a gate which selectively connects the IDE bus with the IDE device;

a set of registers for storing information indicative of a current state of the IDE bus; and

means for transferring the contents of the set of registers to the IDE device when the IDE bus is connected to the IDE device.

22. The apparatus of claim 19, wherein the interface circuit further comprises an initializer for initializing a master/slave status of the IDE device.

23. An interface apparatus which fits into a peripheral slot of a host computer, the host computer having an IDE bus, the interface apparatus comprising:

an interface frame having an internal bay which accommodates an IDE device, the interface frame being insertable into the peripheral slot of the host computer;

an interface circuit which, while the IDE bus is active and while the IDE device is being inserted into the internal bay of the interface frame, keeps the IDE device isolated from the IDE bus until a predetermined electrical condition of the IDE device is sensed;

wherein the predetermined electrical condition of the IDE device is that the IDE device has completed its own initialization.

24. The apparatus of claim 23, wherein the interface circuit is mounted on the interface frame.

25. The apparatus of claim 23, wherein the interface circuit comprises:

an insertion/removal detector which detects whether the IDE device is inserted into the bay of the interface frame;

a gate which selectively connects the IDE bus with the IDE device;

a set of registers for storing information indicative of a current state of the IDE bus; and

means for transferring the contents of the set of registers to the IDE device when the IDE bus is connected to the IDE device.

26. The apparatus of claim 23, wherein the interface circuit further comprises an initializer for initializing a master/slave status of the IDE device.

27. A computer system comprising:

a microprocessor;

an IDE adapter connected to the microprocessor;

an IDE bus connected between the IDE adapter;

an interface apparatus connected to the IDE bus and to which an IDE device is connectable while the IDE bus is active, the interface device keeping the IDE device isolated from the IDE bus until a predetermined electrical condition of the IDE device is sensed;

wherein the predetermined electrical condition of the IDE device is sensed by sensing a predetermined signal issued by the IDE device.

28. The apparatus of claim 27, wherein the interface apparatus comprises:

an insertion/removal detector which detects whether the IDE device is inserted into the bay of the interface frame;

a gate which selectively connects the IDE bus with the IDE device;

a set of registers for storing information indicative of a current state of the IDE bus; and

means for transferring the contents of the set of registers to the IDE device when the IDE bus is connected to the IDE device.

29. The apparatus of claim 27, wherein the interface apparatus further comprises an initializer for initializing a master/slave status of the IDE device.

30. A computer system comprising:

a microprocessor;

an IDE adapter connected to the microprocessor;

an IDE bus connected between the IDE adapter;

an interface apparatus connected to the IDE bus and to which an IDE device is connectable while the IDE bus is active, the interface device keeping the IDE device isolated from the IDE bus until a predetermined electrical condition of the IDE device is sensed;

wherein the predetermined electrical condition of the IDE device is sensed by reading a task file of the IDE device.

31. The apparatus of claim 30, wherein the interface apparatus comprises:

an insertion/removal detector which detects whether the IDE device is inserted into the bay of the interface frame;

a gate which selectively connects the IDE bus with the IDE device;

a set of registers for storing information indicative of a current state of the IDE bus; and

means for transferring the contents of the set of registers to the IDE device when the IDE bus is connected to the IDE device.

32. The apparatus of claim 30, wherein the interface apparatus further comprises an initializer for initializing a master/slave status of the IDE device.

33. A computer system comprising:

a microprocessor;

an IDE adapter connected to the microprocessor;

an IDE bus connected between the IDE adapter;

an interface apparatus connected to the IDE bus and to which an IDE device is connectable while the IDE bus is active, the interface device keeping the IDE device isolated from the IDE bus until a predetermined electrical condition of the IDE device is sensed;

wherein the predetermined electrical condition of the IDE device is that the IDE device has completed its own initialization.

34. The apparatus of claim 33, wherein the interface apparatus comprises:

an insertion/removal detector which detects whether the IDE device is inserted into the bay of the interface frame;

a gate which selectively connects the IDE bus with the IDE device;

a set of registers for storing information indicative of a current state of the IDE bus; and

means for transferring the contents of the set of registers to the IDE device when the IDE bus is connected to the IDE device.

35. The apparatus of claim 33, wherein the interface apparatus further comprises an initializer for initializing a master/slave status of the IDE device.

36. A computer system comprising:

a microprocessor;

an IDE bus connected to the microprocessor;

an interface apparatus connected to the IDE bus and to which an IDE device is connectable while the IDE bus is active;

wherein the microprocessor maintains a dynamic device database and wherein the microprocessor causes reenumeration of the database to reflect connection or disconnection of the IDE device relative to the interface apparatus while the IDE bus is active;

wherein the microprocessor executes a driver which causes the reenumeration of the database.

37. The computer system of claim 36, wherein the driver resides in and is executed in a first ring of an operating system of the microprocessor,

wherein the driver schedules execution of at least a portion of the driver in a second ring of the operating system for the purpose of removing, during a time of execution of the second ring, a node of the dynamic device database which is a parent to the IDE device which as been connected or disconnected to the interface apparatus, and wherein the driver requests at least a partial inventory of the computer system during execution of the first ring in order to reenumerate the database.