公开(公告)号：DE2963641D1

公开(公告)日：1982-10-28

申请号：DE2963641

申请日：1979-07-16

Applicant: IBM

Inventor： CONNER DAVID EUGENE ,  HOFFMAN CHARLES REEVES ,  LAAKSO MELVIN THOMAS

IPC: G06F13/00 ,  G06F11/20 ,  H04L12/423 ,  H04L12/437 ,  H04L11/16 ,  G06F11/00

公开(公告)号：DE3279136D1

公开(公告)日：1988-11-24

申请号：DE3279136

申请日：1982-07-13

Applicant: IBM

Inventor： DRAPER WILBURN DOYCE ,  LAAKSO MELVIN THOMAS

IPC: G06F11/00 ,  G06F11/30 ,  G06F13/00 ,  G06F13/12

Abstract: Multi subchannel adapter for a programmed control unit arranged to be operated in facilitating I/O operations between one or more I/O devices and a CPU through a channel, including a local store (17) which comprises a hardware register dedicated to store device status (RNB) and the associated address (RNA) in connection with test I/O commands. Thus, on receiving a status request the adapter responds immediately with a response indicating that the information is not immediately available, for example, a busy response. The adapter initiates an interrupt to the programmed control unit to obtain the requested status information, which is then stored in dedicated hardware register (RNA, RNB) of the local store (17). On the next subsequent test I/O command to the same address, the adapter responds with the status as read from the dedicated hardware register (RNB).