公开(公告)号：BR9104314A

公开(公告)日：1992-06-09

申请号：BR9104314

申请日：1991-10-07

Applicant: IBM

Inventor： ANBROSE JOHN J D ,  SHETTERLY WILLIAM K ,  THOMPSON STEPHEN ,  TURNER MICHAEL R

IPC: G06F13/14 ,  G06F13/10 ,  G06F13/20

Abstract: A hardware-based system for managing multiple input/output devices sharing the same set of addresses in a computer system is described. The new VIRTUAL ENABLED state is a hybrid of the current ENABLED or ACTIVE and DISABLED or INACTIVE states. In the ENABLED state, an I/O adapter responds to I/O addressing and presents interrupts to the processor. In the DISABLED state, the I/O adapter does not respond to I/O addressing and does not present interrupts. In the new VIRTUAL ENABLED state, the adapter does not respond to I/O addressing (as in the DISABLED state), but will still produce an interrupt (as in the ENABLED state). With the VIRTUAL state, multiple I/O adapters that would normally contend for the same set of addresses (ENABLED state), or optionally be rendered inoperable (DISABLED state), can always remain available for I/O. A single register where the processor can read the interrupt status for all ENABLED and/or VIRTUAL ENABLED adapters sharing the same set of addresses is provided. Other unique registers are also provided to allow the processor to cycle any of the ENABLED and VIRTUAL ENABLED devices between these two states to permit servicing of the interrupt.

公开(公告)号：CA2051199A1

公开(公告)日：1992-05-01

申请号：CA2051199

申请日：1991-09-11

Applicant: IBM

Inventor： D AMBROSE JOHN J ,  SHETTERLY WILLIAM K ,  THOMPSON STEPHEN ,  TURNER MICHAEL R

IPC: G06F13/14 ,  G06F13/10

Abstract: A hardware-based system for managing multiple input/output devices sharing the same set of addresses in a computer system is described. The new VIRTUAL ENABLED state is a hybrid of the current ENABLED or ACTIVE and DISABLED or INACTIVE states. In the ENABLED state, an I/O adapter responds to I/O addressing and presents interrupts to the processor. In the DISABLED state, the I/O adapter does not respond to I/O addressing and does not present interrupts. In the new VIRTUAL ENABLED state, the adapter does not respond to I/O addressing (as in the DISABLED state), but will still produce an interrupt (as in the ENABLED state). With the VIRTUAL state, multiple I/O adapters that would normally contend for the same set of addresses (ENABLED state), or optionally be rendered inoperable (DISABLED state), can always remain available for I/O. A single register where the processor can read the interrupt status for all ENABLED and/or VIRTUAL ENABLED adapters sharing the same set of addresses is provided. Other unique registers are also provided to allow the processor to cycle any of the ENABLED and VIRTUAL ENABLED devices between these two states to permit servicing of the interrupt.