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公开(公告)号:IN179860B
公开(公告)日:1997-12-27
申请号:IN903MA1994
申请日:1994-09-15
Applicant: IBM
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公开(公告)号:IN178635B
公开(公告)日:1997-05-24
申请号:IN759MA1990
申请日:1990-09-25
Applicant: IBM
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公开(公告)号:DE3166311D1
公开(公告)日:1984-10-31
申请号:DE3166311
申请日:1981-06-25
Applicant: IBM
Inventor: CHISHOLM DOUGLAS RODERICK , KURTZ HOBART LAMOREE
Abstract: A peripheral device address assignment mechanism is described which does not require the use of plugboards or jumpers. This mechanism enables a host processor to select any desired peripheral device and set its device address to any desired value at any desired time. This is accomplished by providing each peripheral device control unit with a loadable device address register for holding the device address assigned to its peripheral device. Each device control unit is further provided with circuitry responsive to the appearance of a unique I/O command on the processor I/O bus and to the activation of a unique set of the I/O bus data lines by the processor for loading into its device address register the desired device address value as supplied thereto by the processor via the I/O bus.
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公开(公告)号:AU527111B2
公开(公告)日:1983-02-17
申请号:AU4698879
申请日:1979-05-14
Applicant: IBM
Inventor: BROWN LEWIS WRIGHT , CHISHOLM DOUGLAS RODERICK , DIXON JERRY DUANE
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公开(公告)号:AU4698879A
公开(公告)日:1980-01-03
申请号:AU4698879
申请日:1979-05-14
Applicant: IBM
Inventor: BROWN LEWIS WRIGHT , CHISHOLM DOUGLAS RODERICK , DIXON JERRY DUANE
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公开(公告)号:DE69031547T2
公开(公告)日:1998-03-26
申请号:DE69031547
申请日:1990-05-31
Applicant: IBM
Inventor: BONEVENTO FRANCIS MICHAEL , CHISHOLM DOUGLAS RODERICK , DODDS SAMMY DAVIS , DESAI DHRUVKUMAR M , MANDESE ERNEST NELSON
IPC: G06F13/12
Abstract: A Command interface includes ports for transferring information between a host processor and at least one intelligent subsystem which may have attached devices. A Command Interface port receives either a direct command or an indirect command from the host processor, which commands are indicative of a type of operation to be performed by the one subsystem or an attached device. An Attention port receives a code from the host processor which is indicative of which one of the direct command or the indirect command is received at the Command Interface port, and which is also indicative of which of the one intelligent subsystem or a device is to execute the command. A command busy/status port receives a code from the one intelligent subsystem which is indicative of whether or not the Command Interface port and the Attention port are busy, and whether or not the one intelligent subsystem is accepting or rejecting commands. The host processor can read this port without altering or updating the code.
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公开(公告)号:DE69025268T2
公开(公告)日:1996-08-08
申请号:DE69025268
申请日:1990-11-08
Applicant: IBM
Inventor: PADGETT RUSSELL STEPHEN , CHISHOLM DOUGLAS RODERICK , GARCIA SERAFIN JOSE ELEAZAR , ALVAREZ RAFAEL , KALMAN DEAN ALAN , YODER ROBERT DEAN
Abstract: A selected address within one of two segments of a memory space (124) of a second address/data bus (116), can be accessed from a first bus (102) through one of two data registers (136 and 138). In addition, the location of the two segments within the memory space of the second bus is selectable through two segment registers (148 and 150), which are accessed from the first bus through the first data register (136). A two byte wide "mode" register (126 and 128), which can be directly accessed from the first bus, stores data within three ranges. When the mode register data is within the first range, a selected segment register can be accessed through the first data register. A first value within this range selects the first segment register (148), while a second value selects the second segment register (150). Data loaded into the first and second segment registers points to first and second segments of the second memory space, respectively. When the mode register data is within the second range, this data functions as a pointer to select an address within a selected segment. The selected address is accessed through the data registers; the first data register (136) accessing the selected address in the first segment, while the second data register (138) accesses the selected address in the second segment. After a selected address has been accessed, an auto-increment circuit increments the mode register so that the next sequential address in the selected segment can be accessed without having to reload the mode register. When the mode register data is within the third range, the two data registers can be directly accessed from the first bus.
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公开(公告)号:NZ235800A
公开(公告)日:1994-02-25
申请号:NZ23580090
申请日:1990-10-24
Applicant: IBM
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公开(公告)号:DE4035837A1
公开(公告)日:1991-05-16
申请号:DE4035837
申请日:1990-11-10
Applicant: IBM
Inventor: CARCIA JR , CHISHOLM DOUGLAS RODERICK , KALMAN DEAN ALAN , PADGETT RUSSELL STEPHEN , YODER ROBERT DEAN
IPC: G06F13/32 , G06F13/362
Abstract: A plurality of specialized controllers, e.g. 202, 204 & 206, each one adapted to control a particular type of data transfer operation, control the flow of data between a system bus 104 and a local bus 106 on a computer adapter card 102. When the Direct Memory Access DMA controller 202 is controlling a DMA operation on the local bus, certain other controllers 204 & 206 can break-in to the current DMA operation, temporarily halting the DMA operation until the other controller has completed its data transfer operation. To break-in to a DMA operation, handshaking signals between the DMA controller and the local bus interface circuit 212 are temporarily blocked by blocking signals from a break-in logic circuit 210 . The break-in circuit includes a four-state state machine to block the handshaking signals at the appropriate times, and to signal the interrupting controller to begin its data transfer operation. When breaking-in to a DMA operation in this manner, the operation of the DMA controller is not altered; instead, to the DMA controller, it appears that the local bus interface circuit is merely slow to respond with its acknowledge handshake.
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公开(公告)号:AU6455690A
公开(公告)日:1991-05-16
申请号:AU6455690
申请日:1990-10-15
Applicant: IBM
Inventor: GARCIA SERAFIN JOSE ELEAZAR JR , CHISHOLM DOUGLAS RODERICK , KALMAN DEAN ALAN , PADGETT RUSSELL STEPHEN , YODER ROBERT DEAN
IPC: G06F13/32 , G06F13/362 , G06F13/14
Abstract: A plurality of specialized controllers, e.g. 202, 204 & 206, each one adapted to control a particular type of data transfer operation, control the flow of data between a system bus 104 and a local bus 106 on a computer adapter card 102. When the Direct Memory Access DMA controller 202 is controlling a DMA operation on the local bus, certain other controllers 204 & 206 can break-in to the current DMA operation, temporarily halting the DMA operation until the other controller has completed its data transfer operation. To break-in to a DMA operation, handshaking signals between the DMA controller and the local bus interface circuit 212 are temporarily blocked by blocking signals from a break-in logic circuit 210 . The break-in circuit includes a four-state state machine to block the handshaking signals at the appropriate times, and to signal the interrupting controller to begin its data transfer operation. When breaking-in to a DMA operation in this manner, the operation of the DMA controller is not altered; instead, to the DMA controller, it appears that the local bus interface circuit is merely slow to respond with its acknowledge handshake.
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